913 строки
30 KiB
C
913 строки
30 KiB
C
// Copyright (c) Microsoft Corporation
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// SPDX-License-Identifier: MIT
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/**
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* @file
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* @brief This file implements the XDP program type hook and helper functions on eBPF for Windows.
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*/
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#include "ebpf_store_helper.h"
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#include "net_ebpf_ext_xdp.h"
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//
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// Utility functions.
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//
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__forceinline static NTSTATUS
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_net_ebpf_extension_xdp_validate_if_index(uint32_t if_index)
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{
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NTSTATUS status = STATUS_SUCCESS;
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MIB_IF_ROW2* if_row = NULL;
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NET_EBPF_EXT_LOG_ENTRY();
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if_row =
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(MIB_IF_ROW2*)ExAllocatePoolUninitialized(NonPagedPoolNx, sizeof(MIB_IF_ROW2), NET_EBPF_EXTENSION_POOL_TAG);
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if (if_row == NULL) {
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status = STATUS_NO_MEMORY;
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goto Exit;
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}
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memset(if_row, 0, sizeof(MIB_IF_ROW2));
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if_row->InterfaceIndex = if_index;
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status = GetIfEntry2(if_row);
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Exit:
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if (if_row != NULL) {
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ExFreePool(if_row);
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}
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NET_EBPF_EXT_RETURN_NTSTATUS(status);
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}
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//
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// WFP filter related types & globals for XDP hook.
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//
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const net_ebpf_extension_wfp_filter_parameters_t _net_ebpf_extension_xdp_wfp_filter_parameters[] = {
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{&FWPM_LAYER_INBOUND_MAC_FRAME_NATIVE,
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NULL, // Default sublayer.
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&EBPF_HOOK_INBOUND_L2_CALLOUT,
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L"net eBPF xdp hook",
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L"net eBPF xdp hook WFP filter"},
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{&FWPM_LAYER_OUTBOUND_MAC_FRAME_NATIVE,
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NULL, // Default sublayer.
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&EBPF_HOOK_OUTBOUND_L2_CALLOUT,
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L"net eBPF xdp hook",
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L"net eBPF xdp hook WFP filter"}};
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#define NET_EBPF_XDP_FILTER_COUNT EBPF_COUNT_OF(_net_ebpf_extension_xdp_wfp_filter_parameters)
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typedef struct _net_ebpf_extension_xdp_wfp_filter_context
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{
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net_ebpf_extension_wfp_filter_context_t base;
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uint32_t if_index;
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} net_ebpf_extension_xdp_wfp_filter_context_t;
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//
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// XDP Program Information NPI Provider.
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//
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static int
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_net_ebpf_xdp_adjust_head(_Inout_ xdp_md_t* ctx, int delta);
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static ebpf_result_t
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_ebpf_xdp_context_create(
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_In_reads_bytes_opt_(data_size_in) const uint8_t* data_in,
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size_t data_size_in,
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_In_reads_bytes_opt_(context_size_in) const uint8_t* context_in,
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size_t context_size_in,
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_Outptr_ void** context);
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static void
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_ebpf_xdp_context_delete(
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_In_opt_ void* context,
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_Out_writes_bytes_to_(*data_size_out, *data_size_out) uint8_t* data_out,
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_Inout_ size_t* data_size_out,
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_Out_writes_bytes_to_(*context_size_out, *context_size_out) uint8_t* context_out,
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_Inout_ size_t* context_size_out);
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static const void* _ebpf_xdp_helper_functions[] = {(void*)&_net_ebpf_xdp_adjust_head};
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static ebpf_helper_function_addresses_t _ebpf_xdp_helper_function_address_table = {
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EBPF_COUNT_OF(_ebpf_xdp_helper_functions), (uint64_t*)_ebpf_xdp_helper_functions};
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static ebpf_program_data_t _ebpf_xdp_program_data = {
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.program_info = &_ebpf_xdp_program_info,
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.program_type_specific_helper_function_addresses = &_ebpf_xdp_helper_function_address_table,
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.context_create = _ebpf_xdp_context_create,
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.context_destroy = _ebpf_xdp_context_delete,
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.required_irql = DISPATCH_LEVEL,
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};
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static ebpf_extension_data_t _ebpf_xdp_program_info_provider_data = {
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NET_EBPF_EXTENSION_NPI_PROVIDER_VERSION, sizeof(_ebpf_xdp_program_data), &_ebpf_xdp_program_data};
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NPI_MODULEID DECLSPEC_SELECTANY _ebpf_xdp_program_info_provider_moduleid = {sizeof(NPI_MODULEID), MIT_GUID, {0}};
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static net_ebpf_extension_program_info_provider_t* _ebpf_xdp_program_info_provider_context = NULL;
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//
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// XDP Hook NPI Provider.
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//
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ebpf_attach_provider_data_t _net_ebpf_xdp_hook_provider_data;
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ebpf_extension_data_t _net_ebpf_extension_xdp_hook_provider_data = {
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EBPF_ATTACH_PROVIDER_DATA_VERSION, sizeof(_net_ebpf_xdp_hook_provider_data), &_net_ebpf_xdp_hook_provider_data};
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NPI_MODULEID DECLSPEC_SELECTANY _ebpf_xdp_hook_provider_moduleid = {sizeof(NPI_MODULEID), MIT_GUID, {0}};
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static net_ebpf_extension_hook_provider_t* _ebpf_xdp_hook_provider_context = NULL;
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//
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// NMR Registration Helper Routines.
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//
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static ebpf_result_t
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net_ebpf_extension_xdp_on_client_attach(
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_In_ const net_ebpf_extension_hook_client_t* attaching_client,
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_In_ const net_ebpf_extension_hook_provider_t* provider_context)
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{
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ebpf_result_t result = EBPF_SUCCESS;
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const ebpf_extension_data_t* client_data = net_ebpf_extension_hook_client_get_client_data(attaching_client);
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uint32_t if_index;
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uint32_t wild_card_if_index = 0;
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uint32_t filter_count;
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FWPM_FILTER_CONDITION condition = {0};
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net_ebpf_extension_xdp_wfp_filter_context_t* filter_context = NULL;
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NET_EBPF_EXT_LOG_ENTRY();
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// XDP hook clients must always provide data.
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if (client_data == NULL) {
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result = EBPF_INVALID_ARGUMENT;
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goto Exit;
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}
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if (client_data->size > 0) {
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if ((client_data->size != sizeof(uint32_t)) || (client_data->data == NULL)) {
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result = EBPF_INVALID_ARGUMENT;
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goto Exit;
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}
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if_index = *(uint32_t*)client_data->data;
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} else {
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// If the client did not specify any attach parameters, we treat that as a wildcard interface index.
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if_index = wild_card_if_index;
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}
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result = net_ebpf_extension_hook_check_attach_parameter(
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sizeof(if_index), &if_index, &wild_card_if_index, (net_ebpf_extension_hook_provider_t*)provider_context);
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if (result != EBPF_SUCCESS) {
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goto Exit;
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}
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if (client_data->data != NULL) {
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if_index = *(uint32_t*)client_data->data;
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}
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// Set interface index (if non-zero) as WFP filter condition.
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if (if_index != 0) {
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condition.fieldKey = FWPM_CONDITION_INTERFACE_INDEX;
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condition.matchType = FWP_MATCH_EQUAL;
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condition.conditionValue.type = FWP_UINT32;
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condition.conditionValue.uint32 = if_index;
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}
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result = net_ebpf_extension_wfp_filter_context_create(
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sizeof(net_ebpf_extension_xdp_wfp_filter_context_t),
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attaching_client,
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(net_ebpf_extension_wfp_filter_context_t**)&filter_context);
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if (result != EBPF_SUCCESS) {
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goto Exit;
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}
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filter_context->if_index = if_index;
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filter_context->base.filter_ids_count = NET_EBPF_XDP_FILTER_COUNT;
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// Add WFP filters at appropriate layers and set the hook NPI client as the filter's raw context.
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filter_count = NET_EBPF_XDP_FILTER_COUNT;
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result = net_ebpf_extension_add_wfp_filters(
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filter_count,
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_net_ebpf_extension_xdp_wfp_filter_parameters,
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(if_index == 0) ? 0 : 1,
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(if_index == 0) ? NULL : &condition,
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(net_ebpf_extension_wfp_filter_context_t*)filter_context,
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&filter_context->base.filter_ids);
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if (result != EBPF_SUCCESS) {
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goto Exit;
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}
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// Set the filter context as the client context's provider data.
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net_ebpf_extension_hook_client_set_provider_data(
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(net_ebpf_extension_hook_client_t*)attaching_client, filter_context);
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Exit:
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if (result != EBPF_SUCCESS) {
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if (filter_context != NULL) {
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ExFreePool(filter_context);
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}
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}
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NET_EBPF_EXT_RETURN_RESULT(result);
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}
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static void
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_net_ebpf_extension_xdp_on_client_detach(_In_ const net_ebpf_extension_hook_client_t* detaching_client)
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{
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net_ebpf_extension_xdp_wfp_filter_context_t* filter_context =
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(net_ebpf_extension_xdp_wfp_filter_context_t*)net_ebpf_extension_hook_client_get_provider_data(
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detaching_client);
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NET_EBPF_EXT_LOG_ENTRY();
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ASSERT(filter_context != NULL);
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net_ebpf_extension_delete_wfp_filters(filter_context->base.filter_ids_count, filter_context->base.filter_ids);
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net_ebpf_extension_wfp_filter_context_cleanup((net_ebpf_extension_wfp_filter_context_t*)filter_context);
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NET_EBPF_EXT_LOG_EXIT();
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}
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static NTSTATUS
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_net_ebpf_xdp_update_store_entries()
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{
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NTSTATUS status;
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// Update section information.
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uint32_t section_info_count = sizeof(_ebpf_xdp_section_info) / sizeof(ebpf_program_section_info_t);
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status = _ebpf_store_update_section_information(&_ebpf_xdp_section_info[0], section_info_count);
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if (!NT_SUCCESS(status)) {
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return status;
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}
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// Update program information.
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_ebpf_xdp_program_info.program_type_descriptor.program_type = EBPF_PROGRAM_TYPE_XDP;
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status = _ebpf_store_update_program_information(&_ebpf_xdp_program_info, 1);
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return status;
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}
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NTSTATUS
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net_ebpf_ext_xdp_register_providers()
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{
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NTSTATUS status = STATUS_SUCCESS;
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status = _net_ebpf_xdp_update_store_entries();
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if (!NT_SUCCESS(status)) {
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return status;
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}
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const net_ebpf_extension_program_info_provider_parameters_t program_info_provider_parameters = {
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&_ebpf_xdp_program_info_provider_moduleid, &_ebpf_xdp_program_info_provider_data};
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const net_ebpf_extension_hook_provider_parameters_t hook_provider_parameters = {
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&_ebpf_xdp_hook_provider_moduleid, &_net_ebpf_extension_xdp_hook_provider_data};
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NET_EBPF_EXT_LOG_ENTRY();
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_ebpf_xdp_program_info.program_type_descriptor.program_type = EBPF_PROGRAM_TYPE_XDP;
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// Set the program type as the provider module id.
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_ebpf_xdp_program_info_provider_moduleid.Guid = EBPF_PROGRAM_TYPE_XDP;
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status = net_ebpf_extension_program_info_provider_register(
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&program_info_provider_parameters, &_ebpf_xdp_program_info_provider_context);
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if (!NT_SUCCESS(status)) {
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goto Exit;
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}
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_net_ebpf_xdp_hook_provider_data.supported_program_type = EBPF_PROGRAM_TYPE_XDP;
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// Set the attach type as the provider module id.
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_ebpf_xdp_hook_provider_moduleid.Guid = EBPF_ATTACH_TYPE_XDP;
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_net_ebpf_xdp_hook_provider_data.bpf_attach_type = BPF_XDP;
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_net_ebpf_xdp_hook_provider_data.link_type = BPF_LINK_TYPE_XDP;
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status = net_ebpf_extension_hook_provider_register(
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&hook_provider_parameters,
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net_ebpf_extension_xdp_on_client_attach,
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_net_ebpf_extension_xdp_on_client_detach,
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NULL,
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&_ebpf_xdp_hook_provider_context);
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if (status != EBPF_SUCCESS) {
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goto Exit;
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}
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Exit:
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if (!NT_SUCCESS(status)) {
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net_ebpf_ext_xdp_unregister_providers();
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}
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NET_EBPF_EXT_RETURN_NTSTATUS(status);
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}
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void
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net_ebpf_ext_xdp_unregister_providers()
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{
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if (_ebpf_xdp_hook_provider_context) {
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net_ebpf_extension_hook_provider_unregister(_ebpf_xdp_hook_provider_context);
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_ebpf_xdp_hook_provider_context = NULL;
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}
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if (_ebpf_xdp_program_info_provider_context) {
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net_ebpf_extension_program_info_provider_unregister(_ebpf_xdp_program_info_provider_context);
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_ebpf_xdp_program_info_provider_context = NULL;
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}
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}
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/**
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* @brief This is the internal data structure for XDP context.
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*/
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typedef struct _net_ebpf_xdp_md
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{
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xdp_md_t base;
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NET_BUFFER_LIST* original_nbl;
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NET_BUFFER_LIST* cloned_nbl;
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} net_ebpf_xdp_md_t;
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//
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// NBL Clone Functions.
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//
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static void
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_net_ebpf_ext_free_nbl(_Inout_ NET_BUFFER_LIST* nbl, BOOLEAN free_data);
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static NTSTATUS
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_net_ebpf_ext_allocate_cloned_nbl(_Inout_ net_ebpf_xdp_md_t* net_xdp_ctx, uint32_t unused_header_length)
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{
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NTSTATUS status = STATUS_SUCCESS;
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uint8_t* old_data;
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NET_BUFFER_LIST* old_nbl = NULL;
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NET_BUFFER* old_net_buffer = NULL;
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NET_BUFFER_LIST* new_nbl = NULL;
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uint32_t cloned_net_buffer_length = 0;
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uint8_t* packet_buffer = NULL;
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MDL* mdl_chain = NULL;
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// Either original or cloned NBL must be present.
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if ((net_xdp_ctx->original_nbl == NULL) && (net_xdp_ctx->cloned_nbl == NULL)) {
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status = STATUS_INVALID_PARAMETER;
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goto Exit;
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}
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old_data = (uint8_t*)net_xdp_ctx->base.data;
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old_nbl = (net_xdp_ctx->cloned_nbl != NULL) ? net_xdp_ctx->cloned_nbl : net_xdp_ctx->original_nbl;
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ASSERT(old_nbl != NULL);
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old_net_buffer = NET_BUFFER_LIST_FIRST_NB(old_nbl);
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// Allocate buffer for the cloned NBL, accounting for any unused header.
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status = RtlULongAdd(old_net_buffer->DataLength, unused_header_length, (unsigned long*)&cloned_net_buffer_length);
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if (!NT_SUCCESS(status)) {
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goto Exit;
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}
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packet_buffer =
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(uint8_t*)ExAllocatePoolUninitialized(NonPagedPoolNx, cloned_net_buffer_length, NET_EBPF_EXTENSION_POOL_TAG);
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if (packet_buffer == NULL) {
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status = STATUS_INSUFFICIENT_RESOURCES;
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goto Exit;
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}
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RtlZeroMemory(packet_buffer, cloned_net_buffer_length);
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if (old_data != NULL) {
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// Copy the contents of the old NBL into the packet_buffer at the offset after any unused header.
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RtlCopyMemory(packet_buffer + unused_header_length, old_data, old_net_buffer->DataLength);
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} else {
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// This is the case when we received a NB with more than one MDL. Get contiguous data buffer
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// from NB and copy to packet_buffer at the offset after any unused header.
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uint8_t* buffer = (uint8_t*)NdisGetDataBuffer(
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old_net_buffer, old_net_buffer->DataLength, packet_buffer + unused_header_length, 1, 0);
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if (buffer == NULL) {
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status = STATUS_INSUFFICIENT_RESOURCES;
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goto Exit;
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}
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}
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// Adjust the XDP context data pointers.
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net_xdp_ctx->base.data = packet_buffer;
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net_xdp_ctx->base.data_end = packet_buffer + cloned_net_buffer_length;
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// Create a MDL with the packet buffer.
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mdl_chain = IoAllocateMdl(packet_buffer, cloned_net_buffer_length, FALSE, FALSE, NULL);
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if (mdl_chain == NULL) {
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status = STATUS_INSUFFICIENT_RESOURCES;
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goto Exit;
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}
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MmBuildMdlForNonPagedPool(mdl_chain);
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// Now allocate the cloned NBL using this MDL chain.
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status = FwpsAllocateNetBufferAndNetBufferList(
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_net_ebpf_ext_nbl_pool_handle, 0, 0, mdl_chain, 0, cloned_net_buffer_length, &new_nbl);
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if (!NT_SUCCESS(status)) {
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goto Exit;
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}
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mdl_chain = NULL;
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packet_buffer = NULL;
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// Set the new NBL as the cloned NBL in XDP context, after disposing any previous clones.
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if (net_xdp_ctx->cloned_nbl != NULL) {
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_net_ebpf_ext_free_nbl(net_xdp_ctx->cloned_nbl, TRUE);
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}
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net_xdp_ctx->cloned_nbl = new_nbl;
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Exit:
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if (mdl_chain != NULL) {
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IoFreeMdl(mdl_chain);
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}
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if (packet_buffer != NULL) {
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ExFreePool(packet_buffer);
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}
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if (!NT_SUCCESS(status)) {
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NET_EBPF_EXT_LOG_FUNCTION_ERROR(status);
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}
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return status;
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}
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static void
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_net_ebpf_ext_free_nbl(_Inout_ NET_BUFFER_LIST* nbl, BOOLEAN free_data)
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{
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NET_BUFFER* net_buffer = NET_BUFFER_LIST_FIRST_NB(nbl);
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MDL* mdl_chain = NET_BUFFER_FIRST_MDL(net_buffer);
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if (free_data) {
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uint8_t* buffer = (uint8_t*)MmGetSystemAddressForMdlSafe(mdl_chain, NormalPagePriority);
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if (buffer != NULL) {
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ExFreePool(buffer);
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}
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}
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IoFreeMdl(mdl_chain);
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FwpsFreeNetBufferList0(nbl);
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}
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//
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// XDP Helper Functions.
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//
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static int
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_net_ebpf_xdp_adjust_head(_Inout_ xdp_md_t* ctx, int delta)
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{
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int return_value = 0;
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NDIS_STATUS ndis_status = NDIS_STATUS_SUCCESS;
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net_ebpf_xdp_md_t* net_xdp_ctx = (net_ebpf_xdp_md_t*)ctx;
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NET_BUFFER_LIST* nbl = NULL;
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NET_BUFFER* net_buffer = NULL;
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|
uint8_t* packet_buffer = NULL;
|
|
|
|
// Either original or cloned NBL must be present.
|
|
if ((net_xdp_ctx->original_nbl == NULL) && (net_xdp_ctx->cloned_nbl == NULL)) {
|
|
return_value = -1;
|
|
goto Exit;
|
|
}
|
|
|
|
nbl = (net_xdp_ctx->cloned_nbl != NULL) ? net_xdp_ctx->cloned_nbl : net_xdp_ctx->original_nbl;
|
|
ASSERT(nbl != NULL);
|
|
net_buffer = NET_BUFFER_LIST_FIRST_NB(nbl);
|
|
|
|
if (delta == 0) {
|
|
// Nothing to do.
|
|
goto Exit;
|
|
}
|
|
if (delta < 0) {
|
|
uint32_t absolute_delta = -delta;
|
|
ndis_status = NdisRetreatNetBufferDataStart(net_buffer, absolute_delta, 0, NULL);
|
|
if (ndis_status != NDIS_STATUS_SUCCESS) {
|
|
return_value = -1;
|
|
goto Exit;
|
|
}
|
|
packet_buffer = (uint8_t*)NdisGetDataBuffer(net_buffer, net_buffer->DataLength, NULL, 1, 0);
|
|
if (packet_buffer != NULL) {
|
|
net_xdp_ctx->base.data = packet_buffer;
|
|
} else {
|
|
// Data in net_buffer not contiguous.
|
|
// Restore net_buffer.
|
|
NdisAdvanceNetBufferDataStart(net_buffer, absolute_delta, TRUE, NULL);
|
|
// Allocate a cloned NBL with contiguous data.
|
|
_net_ebpf_ext_allocate_cloned_nbl(net_xdp_ctx, absolute_delta);
|
|
}
|
|
} else {
|
|
// delta > 0.
|
|
NdisAdvanceNetBufferDataStart(net_buffer, delta, FALSE, NULL);
|
|
packet_buffer = (uint8_t*)NdisGetDataBuffer(net_buffer, net_buffer->DataLength, NULL, 1, 0);
|
|
ASSERT(packet_buffer != NULL);
|
|
net_xdp_ctx->base.data = packet_buffer;
|
|
}
|
|
|
|
Exit:
|
|
if (return_value == -1) {
|
|
NET_EBPF_EXT_LOG_FUNCTION_ERROR(return_value);
|
|
}
|
|
|
|
return return_value;
|
|
}
|
|
|
|
//
|
|
// Packet Injection Routines.
|
|
//
|
|
|
|
static void
|
|
_net_ebpf_ext_l2_receive_inject_complete(_In_ const void* context, _Inout_ NET_BUFFER_LIST* nbl, BOOLEAN dispatch_level)
|
|
{
|
|
UNREFERENCED_PARAMETER(context);
|
|
UNREFERENCED_PARAMETER(dispatch_level);
|
|
// Free clone allocated using _net_ebpf_ext_allocate_cloned_nbl.
|
|
_net_ebpf_ext_free_nbl(nbl, TRUE);
|
|
}
|
|
|
|
static NTSTATUS
|
|
_net_ebpf_ext_receive_inject_cloned_nbl(
|
|
_In_ const NET_BUFFER_LIST* cloned_nbl, _In_ const FWPS_INCOMING_VALUES* incoming_fixed_values)
|
|
{
|
|
uint32_t interface_index =
|
|
incoming_fixed_values->incomingValue[FWPS_FIELD_INBOUND_MAC_FRAME_NATIVE_INTERFACE_INDEX].value.uint32;
|
|
uint32_t ndis_port =
|
|
incoming_fixed_values->incomingValue[FWPS_FIELD_INBOUND_MAC_FRAME_NATIVE_NDIS_PORT].value.uint32;
|
|
|
|
NTSTATUS status = FwpsInjectMacReceiveAsync(
|
|
_net_ebpf_ext_l2_injection_handle,
|
|
NULL,
|
|
0,
|
|
FWPS_LAYER_INBOUND_MAC_FRAME_NATIVE,
|
|
interface_index,
|
|
ndis_port,
|
|
(NET_BUFFER_LIST*)cloned_nbl,
|
|
(FWPS_INJECT_COMPLETE)_net_ebpf_ext_l2_receive_inject_complete,
|
|
NULL);
|
|
|
|
if (!NT_SUCCESS(status)) {
|
|
NET_EBPF_EXT_LOG_NTSTATUS_API_FAILURE(NET_EBPF_EXT_TRACELOG_KEYWORD_XDP, "FwpsInjectMacReceiveAsync", status);
|
|
goto Exit;
|
|
}
|
|
|
|
Exit:
|
|
if (!NT_SUCCESS(status)) {
|
|
NET_EBPF_EXT_LOG_FUNCTION_ERROR(status);
|
|
}
|
|
|
|
return status;
|
|
}
|
|
|
|
static void
|
|
_net_ebpf_ext_l2_inject_send_complete(
|
|
_In_opt_ const void* context, _Inout_ NET_BUFFER_LIST* nbl, BOOLEAN dispatch_level)
|
|
{
|
|
UNREFERENCED_PARAMETER(dispatch_level);
|
|
|
|
if ((BOOLEAN)(uintptr_t)context == FALSE) {
|
|
// Free clone allocated using _net_ebpf_ext_allocate_cloned_nbl.
|
|
_net_ebpf_ext_free_nbl(nbl, TRUE);
|
|
} else {
|
|
// Free clone allocated using FwpsAllocateCloneNetBufferList.
|
|
FwpsFreeCloneNetBufferList(nbl, 0);
|
|
}
|
|
}
|
|
|
|
static void
|
|
_net_ebpf_ext_handle_xdp_tx(
|
|
_Inout_ net_ebpf_xdp_md_t* net_xdp_ctx, _In_ const FWPS_INCOMING_VALUES* incoming_fixed_values)
|
|
{
|
|
NET_BUFFER_LIST* nbl = NULL;
|
|
NTSTATUS status = STATUS_SUCCESS;
|
|
bool cloned_packet = FALSE;
|
|
|
|
uint32_t interface_index =
|
|
incoming_fixed_values->incomingValue[FWPS_FIELD_INBOUND_MAC_FRAME_NATIVE_INTERFACE_INDEX].value.uint32;
|
|
uint32_t ndis_port =
|
|
incoming_fixed_values->incomingValue[FWPS_FIELD_INBOUND_MAC_FRAME_NATIVE_NDIS_PORT].value.uint32;
|
|
|
|
// Either original or cloned NBL must be present.
|
|
ASSERT((net_xdp_ctx->original_nbl != NULL) || (net_xdp_ctx->cloned_nbl != NULL));
|
|
|
|
if (net_xdp_ctx->cloned_nbl != NULL) {
|
|
// No need to clone an already cloned NBL.
|
|
nbl = net_xdp_ctx->cloned_nbl;
|
|
} else {
|
|
status = FwpsAllocateCloneNetBufferList(net_xdp_ctx->original_nbl, NULL, NULL, 0, &nbl);
|
|
if (status != STATUS_SUCCESS) {
|
|
goto Exit;
|
|
}
|
|
cloned_packet = TRUE;
|
|
}
|
|
|
|
status = FwpsInjectMacSendAsync(
|
|
_net_ebpf_ext_l2_injection_handle,
|
|
NULL,
|
|
0,
|
|
FWPS_LAYER_OUTBOUND_MAC_FRAME_NATIVE,
|
|
interface_index,
|
|
ndis_port,
|
|
nbl,
|
|
(FWPS_INJECT_COMPLETE)_net_ebpf_ext_l2_inject_send_complete,
|
|
(void*)(uintptr_t)cloned_packet);
|
|
|
|
if (status != STATUS_SUCCESS) {
|
|
NET_EBPF_EXT_LOG_NTSTATUS_API_FAILURE(NET_EBPF_EXT_TRACELOG_KEYWORD_XDP, "FwpsInjectMacSendAsync", status);
|
|
_net_ebpf_ext_l2_inject_send_complete(
|
|
(void*)(uintptr_t)cloned_packet, nbl, KeGetCurrentIrql() == DISPATCH_LEVEL);
|
|
goto Exit;
|
|
}
|
|
|
|
Exit:
|
|
|
|
if (!NT_SUCCESS(status)) {
|
|
NET_EBPF_EXT_LOG_FUNCTION_ERROR(status);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
//
|
|
// WFP Classify callback.
|
|
//
|
|
|
|
void
|
|
net_ebpf_ext_layer_2_classify(
|
|
_In_ const FWPS_INCOMING_VALUES* incoming_fixed_values,
|
|
_In_ const FWPS_INCOMING_METADATA_VALUES* incoming_metadata_values,
|
|
_Inout_opt_ void* layer_data,
|
|
_In_opt_ const void* classify_context,
|
|
_In_ const FWPS_FILTER* filter,
|
|
uint64_t flow_context,
|
|
_Inout_ FWPS_CLASSIFY_OUT* classify_output)
|
|
{
|
|
NTSTATUS status = STATUS_SUCCESS;
|
|
NET_BUFFER_LIST* nbl = (NET_BUFFER_LIST*)layer_data;
|
|
NET_BUFFER* net_buffer = NULL;
|
|
uint8_t* packet_buffer;
|
|
uint32_t result = 0;
|
|
net_ebpf_xdp_md_t net_xdp_ctx = {0};
|
|
net_ebpf_extension_xdp_wfp_filter_context_t* filter_context = NULL;
|
|
net_ebpf_extension_hook_client_t* attached_client = NULL;
|
|
uint32_t client_if_index;
|
|
|
|
UNREFERENCED_PARAMETER(incoming_metadata_values);
|
|
UNREFERENCED_PARAMETER(classify_context);
|
|
UNREFERENCED_PARAMETER(flow_context);
|
|
|
|
classify_output->actionType = FWP_ACTION_PERMIT;
|
|
|
|
//
|
|
// WFP MAC layers are implemented using NDIS light-weight filters (LWF).
|
|
// See https://docs.microsoft.com/en-us/windows-hardware/drivers/network/using-layer-2-filtering for details.
|
|
// FwpsInjectMacSendAsync API is used for injecting packets in the outbound direction to implement XDP_TX.
|
|
// For packet injection to work WFP LWF must register packet send-completion handlers with NDIS.
|
|
// This handler is added only if WFP filters/callouts are added in the FWPS_LAYER_OUTBOUND_MAC_FRAME_NATIVE layer.
|
|
// That is why a filter and a callout is added in this layer even though the callout at the outbound layer
|
|
// need not process any outbound packets.
|
|
//
|
|
if (incoming_fixed_values->layerId == FWPS_LAYER_OUTBOUND_MAC_FRAME_NATIVE) {
|
|
goto Done;
|
|
}
|
|
|
|
filter_context = (net_ebpf_extension_xdp_wfp_filter_context_t*)filter->context;
|
|
ASSERT(filter_context != NULL);
|
|
if (filter_context == NULL) {
|
|
goto Done;
|
|
}
|
|
|
|
attached_client = (net_ebpf_extension_hook_client_t*)filter_context->base.client_context;
|
|
if (attached_client == NULL) {
|
|
goto Done;
|
|
}
|
|
|
|
if (!net_ebpf_extension_hook_client_enter_rundown(attached_client)) {
|
|
attached_client = NULL;
|
|
goto Done;
|
|
}
|
|
|
|
if (nbl == NULL) {
|
|
NET_EBPF_EXT_LOG_MESSAGE(NET_EBPF_EXT_TRACELOG_LEVEL_ERROR, NET_EBPF_EXT_TRACELOG_KEYWORD_ERROR, "Null NBL");
|
|
goto Done;
|
|
}
|
|
|
|
net_xdp_ctx.base.ingress_ifindex =
|
|
incoming_fixed_values->incomingValue[FWPS_FIELD_INBOUND_MAC_FRAME_NATIVE_INTERFACE_INDEX].value.uint32;
|
|
|
|
client_if_index = filter_context->if_index;
|
|
ASSERT((client_if_index == 0) || (client_if_index == net_xdp_ctx.base.ingress_ifindex));
|
|
if (client_if_index != 0 && client_if_index != net_xdp_ctx.base.ingress_ifindex) {
|
|
// The client is not interested in this ingress ifindex.
|
|
goto Done;
|
|
}
|
|
|
|
net_xdp_ctx.original_nbl = nbl;
|
|
|
|
net_buffer = NET_BUFFER_LIST_FIRST_NB(nbl);
|
|
if (net_buffer == NULL) {
|
|
NET_EBPF_EXT_LOG_MESSAGE(
|
|
NET_EBPF_EXT_TRACELOG_LEVEL_ERROR, NET_EBPF_EXT_TRACELOG_KEYWORD_ERROR, "net_buffer not present");
|
|
|
|
// nothing to do
|
|
goto Done;
|
|
}
|
|
|
|
packet_buffer = (uint8_t*)NdisGetDataBuffer(net_buffer, net_buffer->DataLength, NULL, sizeof(uint16_t), 0);
|
|
if (!packet_buffer) {
|
|
// Data in net_buffer not contiguous.
|
|
// Allocate a cloned NBL with contiguous data.
|
|
status = _net_ebpf_ext_allocate_cloned_nbl(&net_xdp_ctx, 0);
|
|
if (!NT_SUCCESS(status)) {
|
|
goto Done;
|
|
}
|
|
} else {
|
|
net_xdp_ctx.base.data = packet_buffer;
|
|
net_xdp_ctx.base.data_end = packet_buffer + net_buffer->DataLength;
|
|
}
|
|
|
|
if (net_ebpf_extension_hook_invoke_program(attached_client, &net_xdp_ctx, &result) != EBPF_SUCCESS) {
|
|
// Perform a default action if the program fails.
|
|
result = XDP_DROP;
|
|
}
|
|
|
|
switch (result) {
|
|
case XDP_PASS:
|
|
if (net_xdp_ctx.cloned_nbl != NULL) {
|
|
// Drop the original NBL.
|
|
classify_output->actionType = FWP_ACTION_BLOCK;
|
|
classify_output->rights &= ~FWPS_RIGHT_ACTION_WRITE;
|
|
|
|
// Inject the cloned NBL in receive path.
|
|
status = _net_ebpf_ext_receive_inject_cloned_nbl(net_xdp_ctx.cloned_nbl, incoming_fixed_values);
|
|
if (NT_SUCCESS(status)) {
|
|
// If cloned packet could be successfully injected, no need to audit for dropping the original.
|
|
// So absorb the original packet.
|
|
classify_output->flags |= FWPS_CLASSIFY_OUT_FLAG_ABSORB;
|
|
}
|
|
}
|
|
// No special processing required in the non-clone case.
|
|
// The inbound original NBL will be allowed to proceed in the ingress path.
|
|
break;
|
|
case XDP_TX:
|
|
_net_ebpf_ext_handle_xdp_tx(&net_xdp_ctx, incoming_fixed_values);
|
|
// Absorb the original NBL.
|
|
classify_output->actionType = FWP_ACTION_BLOCK;
|
|
classify_output->rights &= ~FWPS_RIGHT_ACTION_WRITE;
|
|
classify_output->flags |= FWPS_CLASSIFY_OUT_FLAG_ABSORB;
|
|
break;
|
|
default:
|
|
ASSERT(FALSE);
|
|
__fallthrough;
|
|
case XDP_DROP:
|
|
classify_output->actionType = FWP_ACTION_BLOCK;
|
|
classify_output->rights &= ~FWPS_RIGHT_ACTION_WRITE;
|
|
// Do not audit XDP drops.
|
|
classify_output->flags |= FWPS_CLASSIFY_OUT_FLAG_ABSORB;
|
|
// Free cloned NBL, if any.
|
|
if (net_xdp_ctx.cloned_nbl != NULL) {
|
|
_net_ebpf_ext_free_nbl(net_xdp_ctx.cloned_nbl, TRUE);
|
|
}
|
|
break;
|
|
}
|
|
|
|
Done:
|
|
|
|
if (attached_client) {
|
|
net_ebpf_extension_hook_client_leave_rundown(attached_client);
|
|
}
|
|
|
|
if (!NT_SUCCESS(status)) {
|
|
NET_EBPF_EXT_LOG_FUNCTION_ERROR(status);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Build a xdp_md_t context for the eBPF program. This includes copying the packet data and
|
|
* metadata into a contiguous buffer and building an MDL chain for the same.
|
|
*
|
|
* @param[in] data_in The packet data.
|
|
* @param[in] data_size_in The size of the packet data.
|
|
* @param[in] context_in The context.
|
|
* @param[in] context_size_in The size of the context.
|
|
* @param[out] context The context to be passed to the eBPF program.
|
|
* @retval STATUS_SUCCESS The operation was successful.
|
|
* @retval STATUS_INVALID_PARAMETER One or more parameters are incorrect.
|
|
* @retval STATUS_NO_MEMORY Failed to allocate resources for this operation.
|
|
*/
|
|
static ebpf_result_t
|
|
_ebpf_xdp_context_create(
|
|
_In_reads_bytes_opt_(data_size_in) const uint8_t* data_in,
|
|
size_t data_size_in,
|
|
_In_reads_bytes_opt_(context_size_in) const uint8_t* context_in,
|
|
size_t context_size_in,
|
|
_Outptr_ void** context)
|
|
{
|
|
ebpf_result_t result;
|
|
net_ebpf_xdp_md_t* new_context = NULL;
|
|
MDL* mdl_chain = NULL;
|
|
NET_BUFFER_LIST* new_nbl = NULL;
|
|
|
|
NET_EBPF_EXT_LOG_ENTRY();
|
|
|
|
*context = NULL;
|
|
|
|
// Data is mandatory.
|
|
// Context is optional.
|
|
if (data_in == NULL || data_size_in == 0) {
|
|
NET_EBPF_EXT_LOG_MESSAGE(
|
|
NET_EBPF_EXT_TRACELOG_LEVEL_ERROR, NET_EBPF_EXT_TRACELOG_KEYWORD_ERROR, "Data is required");
|
|
result = EBPF_INVALID_ARGUMENT;
|
|
goto Done;
|
|
}
|
|
|
|
new_context = (net_ebpf_xdp_md_t*)ExAllocatePoolUninitialized(
|
|
NonPagedPoolNx, sizeof(net_ebpf_xdp_md_t), NET_EBPF_EXTENSION_POOL_TAG);
|
|
if (new_context == NULL) {
|
|
result = EBPF_NO_MEMORY;
|
|
goto Done;
|
|
}
|
|
|
|
memset(new_context, 0, sizeof(net_ebpf_xdp_md_t));
|
|
|
|
// Create a MDL with the packet buffer.
|
|
mdl_chain = IoAllocateMdl((void*)data_in, (unsigned long)data_size_in, FALSE, FALSE, NULL);
|
|
if (mdl_chain == NULL) {
|
|
result = EBPF_NO_MEMORY;
|
|
goto Done;
|
|
}
|
|
MmBuildMdlForNonPagedPool(mdl_chain);
|
|
|
|
// Now allocate the cloned NBL using this MDL chain.
|
|
if (!NT_SUCCESS(FwpsAllocateNetBufferAndNetBufferList(
|
|
_net_ebpf_ext_nbl_pool_handle, 0, 0, mdl_chain, 0, data_size_in, &new_nbl))) {
|
|
result = EBPF_NO_MEMORY;
|
|
goto Done;
|
|
}
|
|
mdl_chain = NULL;
|
|
|
|
new_context->original_nbl = new_nbl;
|
|
new_nbl = NULL;
|
|
|
|
new_context->base.data = (void*)data_in;
|
|
new_context->base.data_end = (void*)(data_in + data_size_in);
|
|
|
|
if (context_in != NULL && context_size_in >= sizeof(xdp_md_t)) {
|
|
xdp_md_t* xdp_context = (xdp_md_t*)context_in;
|
|
new_context->base.data_meta = xdp_context->data_meta;
|
|
new_context->base.ingress_ifindex = xdp_context->ingress_ifindex;
|
|
}
|
|
|
|
*context = new_context;
|
|
new_context = NULL;
|
|
|
|
result = EBPF_SUCCESS;
|
|
|
|
Done:
|
|
if (new_context) {
|
|
ExFreePool(new_context);
|
|
}
|
|
|
|
if (mdl_chain) {
|
|
IoFreeMdl(mdl_chain);
|
|
}
|
|
|
|
if (new_nbl) {
|
|
FwpsFreeNetBufferList0(new_nbl);
|
|
}
|
|
NET_EBPF_EXT_RETURN_RESULT(result);
|
|
}
|
|
|
|
static void
|
|
_ebpf_xdp_context_delete(
|
|
_In_opt_ void* context,
|
|
_Out_writes_bytes_to_(*data_size_out, *data_size_out) uint8_t* data_out,
|
|
_Inout_ size_t* data_size_out,
|
|
_Out_writes_bytes_to_(*context_size_out, *context_size_out) uint8_t* context_out,
|
|
_Inout_ size_t* context_size_out)
|
|
{
|
|
NET_EBPF_EXT_LOG_ENTRY();
|
|
if (!context) {
|
|
return;
|
|
}
|
|
|
|
net_ebpf_xdp_md_t* xdp_context = (net_ebpf_xdp_md_t*)context;
|
|
|
|
// Copy the packet data to the output buffer.
|
|
if (data_out != NULL && data_size_out != NULL) {
|
|
size_t data_size = *data_size_out;
|
|
size_t xdp_data_size = (char*)(xdp_context->base.data_end) - (char*)(xdp_context->base.data);
|
|
if (data_size > xdp_data_size) {
|
|
data_size = xdp_data_size;
|
|
}
|
|
memcpy(data_out, xdp_context->base.data, data_size);
|
|
*data_size_out = data_size;
|
|
} else {
|
|
*data_size_out = 0;
|
|
}
|
|
|
|
// Copy some fields from the context to the output buffer.
|
|
if (context_out != NULL && context_size_out != NULL) {
|
|
size_t context_size = *context_size_out;
|
|
if (context_size > sizeof(xdp_md_t)) {
|
|
context_size = sizeof(xdp_md_t);
|
|
}
|
|
|
|
xdp_md_t* xdp_context_out = (xdp_md_t*)context_out;
|
|
xdp_context_out->data_meta = xdp_context->base.data_meta;
|
|
xdp_context_out->ingress_ifindex = xdp_context->base.ingress_ifindex;
|
|
*context_size_out = context_size;
|
|
} else {
|
|
*context_size_out = 0;
|
|
}
|
|
|
|
if (xdp_context->original_nbl != NULL) {
|
|
_net_ebpf_ext_free_nbl(xdp_context->original_nbl, FALSE);
|
|
}
|
|
|
|
if (xdp_context->cloned_nbl != NULL) {
|
|
_net_ebpf_ext_free_nbl(xdp_context->cloned_nbl, TRUE);
|
|
}
|
|
|
|
ExFreePool(xdp_context);
|
|
NET_EBPF_EXT_LOG_FUNCTION_SUCCESS();
|
|
}
|