/*
* windivert.c
* (C) 2013, all rights reserved,
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see .
*/
#include
#include
#include
#include
#include
#include
#include "windivert_device.h"
/*
* WDK function declaration cruft.
*/
DRIVER_INITIALIZE DriverEntry;
EVT_WDF_DRIVER_UNLOAD windivert_unload;
EVT_WDF_IO_IN_CALLER_CONTEXT windivert_caller_context;
EVT_WDF_IO_QUEUE_IO_DEVICE_CONTROL windivert_ioctl;
EVT_WDF_DEVICE_FILE_CREATE windivert_create;
EVT_WDF_TIMER windivert_timer;
EVT_WDF_FILE_CLEANUP windivert_cleanup;
EVT_WDF_FILE_CLOSE windivert_close;
KSTART_ROUTINE windivert_read_service_worker;
/*
* Debugging macros.
*/
// #define DEBUG_ON
#define DEBUG_BUFSIZE 256
#ifdef DEBUG_ON
static void DEBUG(PCCH format, ...)
{
va_list args;
char buf[DEBUG_BUFSIZE+1];
if (KeGetCurrentIrql() != PASSIVE_LEVEL)
{
return;
}
va_start(args, format);
RtlStringCbVPrintfA(buf, DEBUG_BUFSIZE, format, args);
DbgPrint("WINDIVERT: %s\n", buf);
va_end(args);
}
static void DEBUG_ERROR(PCCH format, NTSTATUS status, ...)
{
va_list args;
char buf[DEBUG_BUFSIZE+1];
if (KeGetCurrentIrql() != PASSIVE_LEVEL)
{
return;
}
va_start(args, status);
RtlStringCbVPrintfA(buf, DEBUG_BUFSIZE, format, args);
DbgPrint("WINDIVERT: *** ERROR ***: (status = %x): %s\n", status, buf);
va_end(args);
}
#else // DEBUG_ON
#define DEBUG(format, ...)
#define DEBUG_ERROR(format, status, ...)
#endif // DEBUG_ON
#define WINDIVERT_TAG 'viDW'
/*
* WinDivert packet filter.
*/
struct filter_s
{
UINT8 protocol:4; // field's protocol
UINT8 test:4; // Filter test
UINT8 field; // Field of interest
UINT16 success; // Success continuation
UINT16 failure; // Fail continuation
UINT32 arg[4]; // Comparison argument
};
typedef struct filter_s *filter_t;
#define WINDIVERT_FILTER_PROTOCOL_NONE 0
#define WINDIVERT_FILTER_PROTOCOL_IP 1
#define WINDIVERT_FILTER_PROTOCOL_IPV6 2
#define WINDIVERT_FILTER_PROTOCOL_ICMP 3
#define WINDIVERT_FILTER_PROTOCOL_ICMPV6 4
#define WINDIVERT_FILTER_PROTOCOL_TCP 5
#define WINDIVERT_FILTER_PROTOCOL_UDP 6
/*
* WinDivert context information.
*/
#define WINDIVERT_CONTEXT_MAGIC 0xAA5D1C5BC439AA72ull
#define WINDIVERT_CONTEXT_SIZE (sizeof(struct context_s))
#define WINDIVERT_CONTEXT_MAXLAYERS 4
#define WINDIVERT_CONTEXT_OUTBOUND_IPV4_LAYER 0
#define WINDIVERT_CONTEXT_INBOUND_IPV4_LAYER 1
#define WINDIVERT_CONTEXT_OUTBOUND_IPV6_LAYER 2
#define WINDIVERT_CONTEXT_INBOUND_IPV6_LAYER 3
typedef enum
{
WINDIVERT_CONTEXT_STATE_OPENING = 0xA0, // Context is opening.
WINDIVERT_CONTEXT_STATE_OPEN = 0xB1, // Context is open.
WINDIVERT_CONTEXT_STATE_CLOSING = 0xC2, // Context is closing.
WINDIVERT_CONTEXT_STATE_CLOSED = 0xD3, // Context is closed.
WINDIVERT_CONTEXT_STATE_INVALID = 0xE4 // Context is invalid.
} context_state_t;
struct context_s
{
UINT64 magic; // WINDIVERT_CONTEXT_MAGIC
context_state_t state; // Context's state.
KSPIN_LOCK lock; // Context-wide lock.
WDFDEVICE device; // Context's device.
LIST_ENTRY packet_queue; // Packet queue.
ULONG packet_queue_length; // Packet queue length.
ULONG packet_queue_maxlength; // Packet queue max length.
WDFTIMER timer; // Packet timer.
UINT timer_timeout; // Packet timeout (in ms).
BOOL timer_ticktock; // Packet timer ticktock.
WDFQUEUE read_queue; // Read queue.
KEVENT read_event; // Read event.
void *read_thread; // Read thread.
UINT8 layer_0; // Context's layer (initial).
UINT8 layer; // Context's layer.
UINT64 flags_0; // Context's flags (initial).
UINT64 flags; // Context's flags.
UINT32 priority_0; // Context's priority (initial).
UINT32 priority; // Context's priority.
GUID sublayer_guid[WINDIVERT_CONTEXT_MAXLAYERS];
// Sublayer GUIDs.
GUID callout_guid[WINDIVERT_CONTEXT_MAXLAYERS];
// Callout GUIDs.
GUID filter_guid[WINDIVERT_CONTEXT_MAXLAYERS];
// Filter GUIDs.
BOOL registered[WINDIVERT_CONTEXT_MAXLAYERS];
// What is registered?
HANDLE engine_handle; // WFP engine handle.
LONG filter_on; // Is filter on?
filter_t filter; // Packet filter.
};
typedef struct context_s context_s;
typedef struct context_s *context_t;
WDF_DECLARE_CONTEXT_TYPE_WITH_NAME(context_s, windivert_context_get);
/*
* WinDivert Layer information.
*/
typedef void (*windivert_callout_t)(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
struct layer_s
{
wchar_t *sublayer_name; // Sub-layer name.
wchar_t *sublayer_desc; // Sub-layer description.
wchar_t *callout_name; // Call-out name.
wchar_t *callout_desc; // Call-out description.
wchar_t *filter_name; // Filter name.
wchar_t *filter_desc; // Filter description.
GUID guid; // WFP layer GUID.
windivert_callout_t callout; // Call-out.
};
typedef struct layer_s *layer_t;
/*
* WinDivert request context.
*/
struct req_context_s
{
struct windivert_addr_s *addr; // Pointer to address structure.
};
typedef struct req_context_s req_context_s;
typedef struct req_context_s *req_context_t;
WDF_DECLARE_CONTEXT_TYPE_WITH_NAME(req_context_s, windivert_req_context_get);
/*
* WinDivert packet structure.
*/
#define WINDIVERT_PACKET_SIZE (sizeof(struct packet_s))
struct packet_s
{
LIST_ENTRY entry; // Entry for queue
UINT8 direction; // Packet direction
UINT32 if_idx; // Interface index
UINT32 sub_if_idx; // Sub-interface index
BOOL ip_checksum; // IP checksum is valid
BOOL tcp_checksum; // TCP checksum is valid
BOOL udp_checksum; // UDP checksum is valid
BOOL timer_ticktock; // Time-out ticktock
ULONG data_len; // Length of data
char data[]; // Packet data
};
typedef struct packet_s *packet_t;
/*
* WinDivert address definition.
*/
struct windivert_addr_s
{
UINT32 IfIdx;
UINT32 SubIfIdx;
UINT8 Direction;
};
typedef struct windivert_addr_s *windivert_addr_t;
/*
* Header definitions.
*/
struct iphdr
{
UINT8 HdrLength:4;
UINT8 Version:4;
UINT8 TOS;
UINT16 Length;
UINT16 Id;
UINT16 FragOff0;
UINT8 TTL;
UINT8 Protocol;
UINT16 Checksum;
UINT32 SrcAddr;
UINT32 DstAddr;
};
struct ipv6hdr
{
UINT8 TrafficClass0:4;
UINT8 Version:4;
UINT8 FlowLabel0:4;
UINT8 TrafficClass1:4;
UINT16 FlowLabel1;
UINT16 Length;
UINT8 NextHdr;
UINT8 HopLimit;
UINT32 SrcAddr[4];
UINT32 DstAddr[4];
};
struct icmphdr
{
UINT8 Type;
UINT8 Code;
UINT16 Checksum;
UINT32 Body;
};
struct icmpv6hdr
{
UINT8 Type;
UINT8 Code;
UINT16 Checksum;
UINT32 Body;
};
struct tcphdr
{
UINT16 SrcPort;
UINT16 DstPort;
UINT32 SeqNum;
UINT32 AckNum;
UINT16 Reserved1:4;
UINT16 HdrLength:4;
UINT16 Fin:1;
UINT16 Syn:1;
UINT16 Rst:1;
UINT16 Psh:1;
UINT16 Ack:1;
UINT16 Urg:1;
UINT16 Reserved2:2;
UINT16 Window;
UINT16 Checksum;
UINT16 UrgPtr;
};
struct udphdr
{
UINT16 SrcPort;
UINT16 DstPort;
UINT16 Length;
UINT16 Checksum;
};
#define IPHDR_GET_FRAGOFF(hdr) (((hdr)->FragOff0) & 0xFF1F)
#define IPHDR_GET_MF(hdr) (((hdr)->FragOff0) & 0x0020)
#define IPHDR_GET_DF(hdr) (((hdr)->FragOff0) & 0x0040)
#define IPV6HDR_GET_TRAFFICCLASS(hdr) \
((((hdr)->TrafficClass0) << 4) | ((hdr)->TrafficClass1))
#define IPV6HDR_GET_FLOWLABEL(hdr) \
((((UINT32)(hdr)->FlowLabel0) << 16) | ((UINT32)(hdr)->FlowLabel1))
/*
* Misc.
*/
#define UINT8_MAX 0xFF
#define UINT16_MAX 0xFFFF
/*
* Global handles.
*/
HANDLE inject_handle;
HANDLE injectv6_handle;
NDIS_HANDLE pool_handle;
/*
* Prototypes.
*/
extern VOID windivert_ioctl(IN WDFQUEUE queue, IN WDFREQUEST request,
IN size_t in_length, IN size_t out_len, IN ULONG code);
extern NTSTATUS windivert_read(context_t context, WDFREQUEST request);
static void windivert_read_service_worker(PVOID context_0);
static void windivert_read_service(context_t context);
static BOOLEAN windivert_context_verify(context_t context,
context_state_t state);
extern VOID windivert_create(IN WDFDEVICE device, IN WDFREQUEST request,
IN WDFFILEOBJECT object);
static NTSTATUS windivert_register_callouts(context_t context, BOOL is_inbound,
BOOL is_outbound, BOOL is_ipv4, BOOL is_ipv6);
static NTSTATUS windivert_register_callout(context_t context, UINT idx,
layer_t layer);
extern VOID windivert_timer(IN WDFTIMER timer);
extern VOID windivert_cleanup(IN WDFFILEOBJECT object);
extern VOID windivert_close(IN WDFFILEOBJECT object);
extern NTSTATUS windivert_write(context_t context, WDFREQUEST request,
windivert_addr_t addr);
extern void NTAPI windivert_inject_complete(VOID *context,
NET_BUFFER_LIST *packets, BOOLEAN dispatch_level);
static NTSTATUS windivert_notify_callout(IN FWPS_CALLOUT_NOTIFY_TYPE type,
IN const GUID *filter_key, IN const FWPS_FILTER0 *filter);
static void windivert_classify_outbound_network_v4_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static void windivert_classify_inbound_network_v4_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static void windivert_classify_outbound_network_v6_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static void windivert_classify_inbound_network_v6_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static void windivert_classify_forward_network_v4_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static void windivert_classify_forward_network_v6_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static void windivert_classify_callout(IN UINT8 direction, IN UINT32 if_idx,
IN UINT32 sub_if_idx, IN BOOL isipv4,
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result);
static BOOL windivert_queue_packet(context_t context, PNET_BUFFER_LIST buffers,
PNET_BUFFER buffer, UINT8 direction, UINT32 if_idx, UINT32 sub_if_idx);
static void windivert_free_packet(packet_t packet);
static UINT16 windivert_checksum(const void *pseudo_header,
size_t pseudo_header_len, const void *data, size_t size);
static void windivert_update_checksums(void *header, size_t len,
BOOL update_ip, BOOL update_tcp, BOOL update_udp);
static BOOL windivert_filter(PNET_BUFFER buffer, UINT32 if_idx,
UINT32 sub_if_idx, BOOL outbound, filter_t filter);
static filter_t windivert_filter_compile(windivert_ioctl_filter_t ioctl_filter,
size_t ioctl_filter_len);
static void windivert_filter_analyze(filter_t filter, BOOL *is_inbound,
BOOL *is_outbound, BOOL *ip_ipv4, BOOL *is_ipv6);
static BOOL windivert_filter_test(filter_t filter, UINT16 ip, UINT8 protocol,
UINT8 field, UINT32 arg);
/*
* Defined layers.
*/
static struct layer_s layer_inbound_network_ipv4_0 =
{
L"" WINDIVERT_DEVICE_NAME L"_SubLayerInboundNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" sublayer network (inbound IPv4)",
L"" WINDIVERT_DEVICE_NAME L"_CalloutInboundNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" callout network (inbound IPv4)",
L"" WINDIVERT_DEVICE_NAME L"_FilterInboundNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" filter network (inbound IPv4)",
{0},
windivert_classify_inbound_network_v4_callout,
};
static layer_t layer_inbound_network_ipv4 = &layer_inbound_network_ipv4_0;
static struct layer_s layer_outbound_network_ipv4_0 =
{
L"" WINDIVERT_DEVICE_NAME L"_SubLayerOutboundNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" sublayer network (outbound IPv4)",
L"" WINDIVERT_DEVICE_NAME L"_CalloutOutboundNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" callout network (outbound IPv4)",
L"" WINDIVERT_DEVICE_NAME L"_FilterOutboundNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" filter network (outbound IPv4)",
{0},
windivert_classify_outbound_network_v4_callout,
};
static layer_t layer_outbound_network_ipv4 = &layer_outbound_network_ipv4_0;
static struct layer_s layer_inbound_network_ipv6_0 =
{
L"" WINDIVERT_DEVICE_NAME L"_SubLayerInboundNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" sublayer network (inbound IPv6)",
L"" WINDIVERT_DEVICE_NAME L"_CalloutInboundNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" callout network (inbound IPv6)",
L"" WINDIVERT_DEVICE_NAME L"_FilterInboundNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" filter network (inbound IPv6)",
{0},
windivert_classify_inbound_network_v6_callout,
};
static layer_t layer_inbound_network_ipv6 = &layer_inbound_network_ipv6_0;
static struct layer_s layer_outbound_network_ipv6_0 =
{
L"" WINDIVERT_DEVICE_NAME L"_SubLayerOutboundNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" sublayer network (outbound IPv6)",
L"" WINDIVERT_DEVICE_NAME L"_CalloutOutboundNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" callout network (outbound IPv6)",
L"" WINDIVERT_DEVICE_NAME L"_FilterOutboundNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" filter network (outbound IPv6)",
{0},
windivert_classify_outbound_network_v6_callout,
};
static layer_t layer_outbound_network_ipv6 = &layer_outbound_network_ipv6_0;
static struct layer_s layer_forward_network_ipv4_0 =
{
L"" WINDIVERT_DEVICE_NAME L"_SubLayerForwardNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" sublayer network (forward IPv4)",
L"" WINDIVERT_DEVICE_NAME L"_CalloutForwardNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" callout network (forward IPv4)",
L"" WINDIVERT_DEVICE_NAME L"_FilterForwardNetworkIPv4",
L"" WINDIVERT_DEVICE_NAME L" filter network (forward IPv4)",
{0},
windivert_classify_forward_network_v4_callout,
};
static layer_t layer_forward_network_ipv4 = &layer_forward_network_ipv4_0;
static struct layer_s layer_forward_network_ipv6_0 =
{
L"" WINDIVERT_DEVICE_NAME L"_SubLayerForwardNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" sublayer network (forward IPv6)",
L"" WINDIVERT_DEVICE_NAME L"_CalloutForwardNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" callout network (forward IPv6)",
L"" WINDIVERT_DEVICE_NAME L"_FilterForwardNetworkIPv6",
L"" WINDIVERT_DEVICE_NAME L" filter network (forward IPv6)",
{0},
windivert_classify_forward_network_v6_callout,
};
static layer_t layer_forward_network_ipv6 = &layer_forward_network_ipv6_0;
/*
* WinDivert driver entry routine.
*/
extern NTSTATUS DriverEntry(IN PDRIVER_OBJECT driver_obj,
IN PUNICODE_STRING reg_path)
{
WDF_DRIVER_CONFIG config;
WDFDRIVER driver;
PWDFDEVICE_INIT device_init;
WDFDEVICE device;
WDF_FILEOBJECT_CONFIG file_config;
WDF_IO_QUEUE_CONFIG queue_config;
WDFQUEUE queue;
WDF_OBJECT_ATTRIBUTES obj_attrs;
NET_BUFFER_LIST_POOL_PARAMETERS pool_params;
NTSTATUS status;
DECLARE_CONST_UNICODE_STRING(device_name,
L"\\Device\\" WINDIVERT_DEVICE_NAME);
DECLARE_CONST_UNICODE_STRING(dos_device_name,
L"\\??\\" WINDIVERT_DEVICE_NAME);
DEBUG("LOAD: loading WinDivert driver");
// Initialize the layers.
layer_inbound_network_ipv4->guid = FWPM_LAYER_INBOUND_IPPACKET_V4;
layer_outbound_network_ipv4->guid = FWPM_LAYER_OUTBOUND_IPPACKET_V4;
layer_inbound_network_ipv6->guid = FWPM_LAYER_INBOUND_IPPACKET_V6;
layer_outbound_network_ipv6->guid = FWPM_LAYER_OUTBOUND_IPPACKET_V6;
layer_forward_network_ipv4->guid = FWPM_LAYER_IPFORWARD_V4;
layer_forward_network_ipv6->guid = FWPM_LAYER_IPFORWARD_V6;
// Configure ourself as a non-PnP driver:
WDF_DRIVER_CONFIG_INIT(&config, WDF_NO_EVENT_CALLBACK);
config.DriverInitFlags |= WdfDriverInitNonPnpDriver;
config.EvtDriverUnload = windivert_unload;
status = WdfDriverCreate(driver_obj, reg_path, WDF_NO_OBJECT_ATTRIBUTES,
&config, &driver);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create WDF driver", status);
return status;
}
device_init = WdfControlDeviceInitAllocate(driver,
&SDDL_DEVOBJ_SYS_ALL_ADM_ALL);
if (device_init == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to allocate WDF control device init structure",
status);
return status;
}
WdfDeviceInitSetDeviceType(device_init, FILE_DEVICE_NETWORK);
WdfDeviceInitSetIoType(device_init, WdfDeviceIoDirect);
status = WdfDeviceInitAssignName(device_init, &device_name);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create WDF device name", status);
WdfDeviceInitFree(device_init);
return status;
}
WDF_FILEOBJECT_CONFIG_INIT(&file_config, windivert_create, windivert_close,
windivert_cleanup);
WDF_OBJECT_ATTRIBUTES_INIT_CONTEXT_TYPE(&obj_attrs, context_s);
WdfDeviceInitSetFileObjectConfig(device_init, &file_config, &obj_attrs);
WdfDeviceInitSetIoInCallerContextCallback(device_init,
windivert_caller_context);
WDF_OBJECT_ATTRIBUTES_INIT(&obj_attrs);
status = WdfDeviceCreate(&device_init, &obj_attrs, &device);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create WDF control device", status);
WdfDeviceInitFree(device_init);
return status;
}
WDF_IO_QUEUE_CONFIG_INIT_DEFAULT_QUEUE(&queue_config,
WdfIoQueueDispatchParallel);
queue_config.EvtIoRead = NULL;
queue_config.EvtIoWrite = NULL;
queue_config.EvtIoDeviceControl = windivert_ioctl;
WDF_OBJECT_ATTRIBUTES_INIT(&obj_attrs);
status = WdfIoQueueCreate(device, &queue_config, &obj_attrs, &queue);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create default WDF queue", status);
return status;
}
status = WdfDeviceCreateSymbolicLink(device, &dos_device_name);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create device symbolic link", status);
return status;
}
WdfControlFinishInitializing(device);
// Create the packet injection handles.
status = FwpsInjectionHandleCreate0(AF_INET,
FWPS_INJECTION_TYPE_NETWORK | FWPS_INJECTION_TYPE_FORWARD,
&inject_handle);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create WFP packet injection handle", status);
return status;
}
status = FwpsInjectionHandleCreate0(AF_INET6,
FWPS_INJECTION_TYPE_NETWORK | FWPS_INJECTION_TYPE_FORWARD,
&injectv6_handle);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create WFP ipv6 packet injection handle",
status);
FwpsInjectionHandleDestroy0(inject_handle);
return status;
}
// Create the packet pool handle.
RtlZeroMemory(&pool_params, sizeof(pool_params));
pool_params.Header.Type = NDIS_OBJECT_TYPE_DEFAULT;
pool_params.Header.Revision = NET_BUFFER_LIST_POOL_PARAMETERS_REVISION_1;
pool_params.Header.Size = sizeof(pool_params);
pool_params.fAllocateNetBuffer = TRUE;
pool_params.PoolTag = WINDIVERT_TAG;
pool_params.DataSize = 0;
pool_handle = NdisAllocateNetBufferListPool(NULL, &pool_params);
if (pool_handle == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to allocate net buffer list pool", status);
FwpsInjectionHandleDestroy0(inject_handle);
FwpsInjectionHandleDestroy0(injectv6_handle);
return status;
}
return STATUS_SUCCESS;
}
/*
* WinDivert driver unload routine.
*/
extern VOID windivert_unload(IN WDFDRIVER Driver)
{
DEBUG("UNLOAD: unloading the WinDivert driver");
FwpsInjectionHandleDestroy0(inject_handle);
FwpsInjectionHandleDestroy0(injectv6_handle);
NdisFreeNetBufferListPool(pool_handle);
}
/*
* WinDivert context verify.
*/
static BOOLEAN windivert_context_verify(context_t context,
context_state_t state)
{
if (context == NULL)
{
DEBUG_ERROR("failed to verify context; context is NULL",
STATUS_INVALID_HANDLE);
return FALSE;
}
if (context->magic != WINDIVERT_CONTEXT_MAGIC)
{
DEBUG_ERROR("failed to verify context; invalid magic number",
STATUS_INVALID_HANDLE);
return FALSE;
}
if (context->state != state)
{
DEBUG_ERROR("failed to verify context; expected context state %x, "
"found context state %x", STATUS_INVALID_HANDLE, state,
context->state);
return FALSE;
}
return TRUE;
}
/*
* WinDivert create routine.
*/
extern VOID windivert_create(IN WDFDEVICE device, IN WDFREQUEST request,
IN WDFFILEOBJECT object)
{
WDF_IO_QUEUE_CONFIG queue_config;
WDF_TIMER_CONFIG timer_config;
WDF_OBJECT_ATTRIBUTES timer_attributes;
FWPM_SESSION0 session;
HANDLE thread;
NTSTATUS status = STATUS_SUCCESS;
UINT8 i;
context_t context = windivert_context_get(object);
DEBUG("CREATE: creating a new WinDivert context (context=%p)", context);
// Initialise the new context:
context->magic = WINDIVERT_CONTEXT_MAGIC;
context->state = WINDIVERT_CONTEXT_STATE_OPENING;
context->device = device;
context->packet_queue_length = 0;
context->packet_queue_maxlength = WINDIVERT_PARAM_QUEUE_LEN_DEFAULT;
context->timer_timeout = WINDIVERT_PARAM_QUEUE_TIME_DEFAULT;
context->layer_0 = WINDIVERT_LAYER_DEFAULT;
context->layer = WINDIVERT_LAYER_DEFAULT;
context->flags_0 = 0;
context->flags = 0;
context->priority_0 = WINDIVERT_PRIORITY_DEFAULT;
context->priority = WINDIVERT_PRIORITY_DEFAULT;
context->read_thread = NULL;
context->filter = NULL;
for (i = 0; i < WINDIVERT_CONTEXT_MAXLAYERS; i++)
{
context->registered[i] = FALSE;
}
context->filter_on = FALSE;
KeInitializeSpinLock(&context->lock);
InitializeListHead(&context->packet_queue);
for (i = 0; i < WINDIVERT_CONTEXT_MAXLAYERS; i++)
{
status = ExUuidCreate(&context->sublayer_guid[i]);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create sub-layer GUID", status);
goto windivert_create_exit;
}
status = ExUuidCreate(&context->callout_guid[i]);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create callout GUID", status);
goto windivert_create_exit;
}
status = ExUuidCreate(&context->filter_guid[i]);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create filter GUID", status);
goto windivert_create_exit;
}
}
WDF_IO_QUEUE_CONFIG_INIT(&queue_config, WdfIoQueueDispatchManual);
status = WdfIoQueueCreate(device, &queue_config, WDF_NO_OBJECT_ATTRIBUTES,
&context->read_queue);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create I/O read queue", status);
goto windivert_create_exit;
}
KeInitializeEvent(&context->read_event, NotificationEvent, FALSE);
status = PsCreateSystemThread(&thread, THREAD_ALL_ACCESS, NULL, NULL,
NULL, windivert_read_service_worker, (PVOID)context);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create read service thread", status);
goto windivert_create_exit;
}
status = ObReferenceObjectByHandle(thread, 0, NULL, KernelMode,
&context->read_thread, NULL);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create read service thread object", status);
goto windivert_create_exit;
}
WDF_TIMER_CONFIG_INIT(&timer_config, windivert_timer);
timer_config.AutomaticSerialization = TRUE;
WDF_OBJECT_ATTRIBUTES_INIT(&timer_attributes);
timer_attributes.ParentObject = (WDFOBJECT)object;
status = WdfTimerCreate(&timer_config, &timer_attributes, &context->timer);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create packet time-out timer", status);
goto windivert_create_exit;
}
RtlZeroMemory(&session, sizeof(session));
session.flags |= FWPM_SESSION_FLAG_DYNAMIC;
status = FwpmEngineOpen0(NULL, RPC_C_AUTHN_DEFAULT, NULL, &session,
&context->engine_handle);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create WFP engine handle", status);
goto windivert_create_exit;
}
context->state = WINDIVERT_CONTEXT_STATE_OPEN;
windivert_create_exit:
// Clean-up on error:
if (!NT_SUCCESS(status))
{
context->state = WINDIVERT_CONTEXT_STATE_INVALID;
if (context->read_queue != NULL)
{
WdfObjectDelete(context->read_queue);
}
if (context->timer != NULL)
{
WdfObjectDelete(context->timer);
}
if (context->engine_handle != NULL)
{
FwpmEngineClose0(context->engine_handle);
}
if (context->read_thread != NULL)
{
KeSetEvent(&context->read_event, IO_NO_INCREMENT, FALSE);
KeWaitForSingleObject(context->read_thread, Executive,
KernelMode, FALSE, NULL);
ObDereferenceObject(context->read_thread);
}
}
WdfRequestComplete(request, status);
}
/*
* Register all WFP callouts.
*/
static NTSTATUS windivert_register_callouts(context_t context, BOOL is_inbound,
BOOL is_outbound, BOOL is_ipv4, BOOL is_ipv6)
{
UINT8 i, j;
layer_t layers[WINDIVERT_CONTEXT_MAXLAYERS];
NTSTATUS status;
i = 0;
switch (context->layer)
{
case WINDIVERT_LAYER_NETWORK:
if (is_inbound && is_ipv4)
{
layers[i++] = layer_inbound_network_ipv4;
}
if (is_outbound && is_ipv4)
{
layers[i++] = layer_outbound_network_ipv4;
}
if (is_inbound && is_ipv6)
{
layers[i++] = layer_inbound_network_ipv6;
}
if (is_outbound && is_ipv6)
{
layers[i++] = layer_outbound_network_ipv6;
}
break;
case WINDIVERT_LAYER_NETWORK_FORWARD:
if (is_ipv4)
{
layers[i++] = layer_forward_network_ipv4;
}
if (is_ipv6)
{
layers[i++] = layer_forward_network_ipv6;
}
break;
default:
return STATUS_INVALID_PARAMETER;
}
status = FwpmTransactionBegin0(context->engine_handle, 0);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to begin WFP transaction", status);
goto windivert_register_callouts_exit;
}
for (j = 0; j < i; j++)
{
status = windivert_register_callout(context, j, layers[j]);
if (!NT_SUCCESS(status))
{
FwpmTransactionAbort0(context->engine_handle);
goto windivert_register_callouts_exit;
}
}
status = FwpmTransactionCommit0(context->engine_handle);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to commit WFP transaction", status);
goto windivert_register_callouts_exit;
}
windivert_register_callouts_exit:
if (!NT_SUCCESS(status))
{
for (j = 0; j < i; j++)
{
if (context->registered[j])
{
FwpsCalloutUnregisterByKey0(&context->callout_guid[j]);
context->registered[j] = FALSE;
}
}
}
return status;
}
/*
* Register a WFP callout.
*/
static NTSTATUS windivert_register_callout(context_t context, UINT idx,
layer_t layer)
{
FWPM_SUBLAYER0 sublayer;
FWPS_CALLOUT0 scallout;
FWPM_CALLOUT0 mcallout;
FWPM_FILTER0 filter;
BOOL registered = FALSE;
NTSTATUS status;
RtlZeroMemory(&sublayer, sizeof(sublayer));
sublayer.subLayerKey = context->sublayer_guid[idx];
sublayer.displayData.name = layer->sublayer_name;
sublayer.displayData.description = layer->sublayer_desc;
sublayer.weight =
(UINT16)(WINDIVERT_PRIORITY_MAX - context->priority);
RtlZeroMemory(&scallout, sizeof(scallout));
scallout.calloutKey = context->callout_guid[idx];
scallout.classifyFn = layer->callout;
scallout.notifyFn = windivert_notify_callout;
scallout.flowDeleteFn = NULL;
RtlZeroMemory(&mcallout, sizeof(mcallout));
mcallout.calloutKey = context->callout_guid[idx];
mcallout.displayData.name = layer->callout_name;
mcallout.displayData.description = layer->callout_desc;
mcallout.applicableLayer = layer->guid;
RtlZeroMemory(&filter, sizeof(filter));
filter.filterKey = context->filter_guid[idx];
filter.layerKey = layer->guid;
filter.displayData.name = layer->filter_name;
filter.displayData.description = layer->filter_desc;
filter.action.type = FWP_ACTION_CALLOUT_TERMINATING;
filter.action.calloutKey = context->callout_guid[idx];
filter.subLayerKey = context->sublayer_guid[idx];
filter.weight.type = FWP_EMPTY;
filter.rawContext = (UINT64)context;
status = FwpmSubLayerAdd0(context->engine_handle, &sublayer, NULL);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to add WFP sub-layer", status);
goto windivert_register_callout_error;
}
status = FwpsCalloutRegister0(WdfDeviceWdmGetDeviceObject(context->device),
&scallout, NULL);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to register WFP callout", status);
goto windivert_register_callout_error;
}
registered = TRUE;
status = FwpmCalloutAdd0(context->engine_handle, &mcallout, NULL, NULL);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to add WFP callout", status);
goto windivert_register_callout_error;
}
status = FwpmFilterAdd0(context->engine_handle, &filter, NULL, NULL);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to add WFP filter", status);
goto windivert_register_callout_error;
}
context->registered[idx] = TRUE;
return STATUS_SUCCESS;
windivert_register_callout_error:
if (registered)
{
FwpsCalloutUnregisterByKey0(&context->callout_guid[idx]);
}
return status;
}
/*
* WinDivert old-packet cleanup routine.
*/
extern VOID windivert_timer(IN WDFTIMER timer)
{
KLOCK_QUEUE_HANDLE lock_handle;
PLIST_ENTRY entry;
WDFFILEOBJECT object = (WDFFILEOBJECT)WdfTimerGetParentObject(timer);
context_t context = windivert_context_get(object);
packet_t packet;
if (!windivert_context_verify(context, WINDIVERT_CONTEXT_STATE_OPEN))
{
return;
}
// DEBUG("TIMER (context=%p, ticktock=%u)", context,
// context->timer_ticktock);
// Sweep away old packets.
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
while (!IsListEmpty(&context->packet_queue))
{
entry = RemoveHeadList(&context->packet_queue);
packet = CONTAINING_RECORD(entry, struct packet_s, entry);
if (packet->timer_ticktock == context->timer_ticktock)
{
InsertHeadList(&context->packet_queue, entry);
break;
}
context->packet_queue_length--;
KeReleaseInStackQueuedSpinLock(&lock_handle);
// Packet is old, dispose of it.
DEBUG("TIMEOUT (context=%p, packet=%p)", context, packet);
windivert_free_packet(packet);
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
}
KeReleaseInStackQueuedSpinLock(&lock_handle);
context->timer_ticktock = !context->timer_ticktock;
// Restart the timer.
WdfTimerStart(context->timer,
WDF_REL_TIMEOUT_IN_MS(context->timer_timeout));
}
/*
* Divert cleanup routine.
*/
extern VOID windivert_cleanup(IN WDFFILEOBJECT object)
{
KLOCK_QUEUE_HANDLE lock_handle;
PLIST_ENTRY entry;
UINT i;
context_t context = windivert_context_get(object);
packet_t packet;
NTSTATUS status;
DEBUG("CLEANUP: cleaning up WinDivert context (context=%p)", context);
if (!windivert_context_verify(context, WINDIVERT_CONTEXT_STATE_OPEN))
{
return;
}
WdfTimerStop(context->timer, TRUE);
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
context->state = WINDIVERT_CONTEXT_STATE_CLOSING;
KeSetEvent(&context->read_event, IO_NO_INCREMENT, FALSE);
while (!IsListEmpty(&context->packet_queue))
{
entry = RemoveHeadList(&context->packet_queue);
KeReleaseInStackQueuedSpinLock(&lock_handle);
packet = CONTAINING_RECORD(entry, struct packet_s, entry);
windivert_free_packet(packet);
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
}
KeReleaseInStackQueuedSpinLock(&lock_handle);
WdfIoQueuePurge(context->read_queue, NULL, NULL);
WdfObjectDelete(context->read_queue);
WdfObjectDelete(context->timer);
status = FwpmTransactionBegin0(context->engine_handle, 0);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to begin WFP transaction", status);
goto windivert_cleanup_exit;
}
for (i = 0; i < WINDIVERT_CONTEXT_MAXLAYERS; i++)
{
if (!context->registered[i])
{
continue;
}
status = FwpmFilterDeleteByKey0(context->engine_handle,
context->filter_guid+i);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed delete WFP filter", status);
FwpmTransactionAbort0(context->engine_handle);
goto windivert_cleanup_exit;
}
status = FwpmSubLayerDeleteByKey0(context->engine_handle,
context->sublayer_guid+i);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed delete WFP sub-layer", status);
FwpmTransactionAbort0(context->engine_handle);
goto windivert_cleanup_exit;
}
}
status = FwpmTransactionCommit0(context->engine_handle);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to commit WFP transaction", status);
goto windivert_cleanup_exit;
}
windivert_cleanup_exit:
FwpmEngineClose0(context->engine_handle);
for (i = 0; i < WINDIVERT_CONTEXT_MAXLAYERS; i++)
{
if (context->registered[i])
{
FwpsCalloutUnregisterByKey0(&context->callout_guid[i]);
}
}
if (context->filter != NULL)
{
ExFreePoolWithTag(context->filter, WINDIVERT_TAG);
context->filter = NULL;
}
KeWaitForSingleObject(context->read_thread, Executive, KernelMode, FALSE,
NULL);
ObDereferenceObject(context->read_thread);
}
/*
* WinDivert close routine.
*/
extern VOID windivert_close(IN WDFFILEOBJECT object)
{
context_t context = windivert_context_get(object);
DEBUG("CLOSE: closing WinDivert context (context=%p)", context);
if (!windivert_context_verify(context, WINDIVERT_CONTEXT_STATE_CLOSING))
{
return;
}
context->state = WINDIVERT_CONTEXT_STATE_CLOSED;
}
/*
* WinDivert read routine.
*/
static NTSTATUS windivert_read(context_t context, WDFREQUEST request)
{
NTSTATUS status = STATUS_SUCCESS;
DEBUG("READ: reading diverted packet (context=%p, request=%p)", context,
request);
// Forward the request to the pending read queue:
status = WdfRequestForwardToIoQueue(request, context->read_queue);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to forward I/O request to read queue", status);
return status;
}
// Service the read request:
windivert_read_service(context);
return STATUS_SUCCESS;
}
/*
* Handle windivert_read_service worker.
*/
static void windivert_read_service_worker(PVOID context_0)
{
KLOCK_QUEUE_HANDLE lock_handle;
context_t context = (context_t)context_0;
/*
* NOTE: We cannot verify the context because we do not know what state
* it is in.
*/
while (TRUE)
{
KeWaitForSingleObject(&context->read_event, Executive, KernelMode,
FALSE, NULL);
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
KeClearEvent(&context->read_event);
if (context->state != WINDIVERT_CONTEXT_STATE_OPEN)
{
break;
}
KeReleaseInStackQueuedSpinLock(&lock_handle);
// Service reads:
windivert_read_service(context);
}
KeReleaseInStackQueuedSpinLock(&lock_handle);
PsTerminateSystemThread(STATUS_SUCCESS);
}
/*
* WinDivert read request service.
*/
static void windivert_read_service(context_t context)
{
KLOCK_QUEUE_HANDLE lock_handle;
WDFREQUEST request;
PLIST_ENTRY entry;
PMDL dst_mdl;
PVOID dst, src;
ULONG dst_len, src_len;
NTSTATUS status;
packet_t packet;
req_context_t req_context;
windivert_addr_t addr;
DEBUG("windivert_read_service");
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
while (context->state == WINDIVERT_CONTEXT_STATE_OPEN &&
!IsListEmpty(&context->packet_queue))
{
status = WdfIoQueueRetrieveNextRequest(context->read_queue, &request);
if (!NT_SUCCESS(status))
{
break;
}
entry = RemoveHeadList(&context->packet_queue);
context->packet_queue_length--;
KeReleaseInStackQueuedSpinLock(&lock_handle);
packet = CONTAINING_RECORD(entry, struct packet_s, entry);
DEBUG("SERVICE: servicing read request (context=%p, request=%p, "
"packet=%p)", context, request, packet);
// We have now have a read request and a packet; service the read.
status = WdfRequestRetrieveOutputWdmMdl(request, &dst_mdl);
dst_len = 0;
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to retrieve output MDL", status);
goto windivert_read_service_complete;
}
dst = MmGetSystemAddressForMdlSafe(dst_mdl, NormalPagePriority);
if (dst == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to get address of output MDL", status);
goto windivert_read_service_complete;
}
dst_len = MmGetMdlByteCount(dst_mdl);
src_len = packet->data_len;
dst_len = (src_len < dst_len? src_len: dst_len);
RtlCopyMemory(dst, packet->data, dst_len);
// Write the address information.
req_context = windivert_req_context_get(request);
addr = req_context->addr;
if (addr != NULL)
{
addr->IfIdx = packet->if_idx;
addr->SubIfIdx = packet->sub_if_idx;
addr->Direction = packet->direction;
}
// Compute the IP/TCP/UDP checksums here (if required).
if ((context->flags & WINDIVERT_FLAG_NO_CHECKSUM) == 0)
{
windivert_update_checksums(dst, dst_len, packet->ip_checksum,
packet->tcp_checksum, packet->udp_checksum);
}
status = STATUS_SUCCESS;
windivert_read_service_complete:
windivert_free_packet(packet);
if (NT_SUCCESS(status))
{
WdfRequestCompleteWithInformation(request, status, dst_len);
}
else
{
WdfRequestComplete(request, status);
}
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
}
KeReleaseInStackQueuedSpinLock(&lock_handle);
}
/*
* WinDivert write routine.
*/
static NTSTATUS windivert_write(context_t context, WDFREQUEST request,
windivert_addr_t addr)
{
PMDL mdl = NULL, mdl_copy = NULL;
PVOID data, data_copy = NULL;
UINT data_len;
struct iphdr *ip_header;
struct ipv6hdr *ipv6_header;
BOOL isipv4;
HANDLE handle;
PNET_BUFFER_LIST buffers = NULL;
NTSTATUS status = STATUS_SUCCESS;
DEBUG("WRITE: writing/injecting a packet (context=%p, request=%p)",
context, request);
if (!windivert_context_verify(context, WINDIVERT_CONTEXT_STATE_OPEN))
{
status = STATUS_INVALID_DEVICE_STATE;
goto windivert_write_exit;
}
if (addr->Direction != WINDIVERT_DIRECTION_INBOUND &&
addr->Direction != WINDIVERT_DIRECTION_OUTBOUND)
{
status = STATUS_INVALID_PARAMETER;
DEBUG_ERROR("failed to inject packet; invalid direction", status);
goto windivert_write_exit;
}
status = WdfRequestRetrieveOutputWdmMdl(request, &mdl);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to retrieve input MDL", status);
goto windivert_write_exit;
}
data = MmGetSystemAddressForMdlSafe(mdl, NormalPagePriority);
if (data == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to get MDL address", status);
goto windivert_write_exit;
}
data_len = MmGetMdlByteCount(mdl);
if (data_len > UINT16_MAX || data_len < sizeof(struct iphdr))
{
windivert_write_bad_packet:
status = STATUS_INVALID_PARAMETER;
DEBUG_ERROR("failed to inject a bad packet", status);
goto windivert_write_exit;
}
data_copy = ExAllocatePoolWithTag(NonPagedPool, data_len, WINDIVERT_TAG);
if (data_copy == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to allocate memory for injected packet data",
status);
goto windivert_write_exit;
}
RtlCopyMemory(data_copy, data, sizeof(struct iphdr));
ip_header = (struct iphdr *)data_copy;
switch (ip_header->Version)
{
case 4:
if (data_len != RtlUshortByteSwap(ip_header->Length))
goto windivert_write_bad_packet;
isipv4 = TRUE;
break;
case 6:
if (data_len < sizeof(struct ipv6hdr))
goto windivert_write_bad_packet;
ipv6_header = (struct ipv6hdr *)data_copy;
if (data_len != RtlUshortByteSwap(ipv6_header->Length) +
sizeof(struct ipv6hdr))
goto windivert_write_bad_packet;
isipv4 = FALSE;
break;
default:
goto windivert_write_bad_packet;
}
if (data_len > sizeof(struct iphdr))
{
RtlCopyMemory((char *)data_copy + sizeof(struct iphdr),
(char *)data + sizeof(struct iphdr),
data_len - sizeof(struct iphdr));
}
mdl_copy = IoAllocateMdl(data_copy, data_len, FALSE, FALSE, NULL);
if (mdl_copy == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to allocate MDL for injected packet", status);
goto windivert_write_exit;
}
MmBuildMdlForNonPagedPool(mdl_copy);
status = FwpsAllocateNetBufferAndNetBufferList0(pool_handle, 0, 0,
mdl_copy, 0, data_len, &buffers);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to create NET_BUFFER_LIST for injected packet",
status);
goto windivert_write_exit;
}
handle = (isipv4? inject_handle: injectv6_handle);
if (context->layer == WINDIVERT_LAYER_NETWORK_FORWARD)
{
status = FwpsInjectForwardAsync0(handle, (HANDLE)context->priority,
0, (isipv4? AF_INET: AF_INET6), UNSPECIFIED_COMPARTMENT_ID,
addr->IfIdx, buffers, windivert_inject_complete, (HANDLE)request);
}
else if (addr->Direction == WINDIVERT_DIRECTION_OUTBOUND)
{
status = FwpsInjectNetworkSendAsync0(handle,
(HANDLE)context->priority, 0, UNSPECIFIED_COMPARTMENT_ID, buffers,
windivert_inject_complete, (HANDLE)request);
}
else
{
status = FwpsInjectNetworkReceiveAsync0(handle,
(HANDLE)context->priority, 0, UNSPECIFIED_COMPARTMENT_ID,
addr->IfIdx, addr->SubIfIdx, buffers, windivert_inject_complete,
(HANDLE)request);
}
windivert_write_exit:
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to (re)inject packet", status);
if (buffers != NULL)
{
FwpsFreeNetBufferList0(buffers);
}
if (mdl_copy != NULL)
{
IoFreeMdl(mdl_copy);
}
if (data_copy != NULL)
{
ExFreePoolWithTag(data_copy, WINDIVERT_TAG);
}
}
return status;
}
/*
* WinDivert inject complete routine.
*/
static void NTAPI windivert_inject_complete(VOID *context,
NET_BUFFER_LIST *buffers, BOOLEAN dispatch_level)
{
WDFREQUEST request = (WDFREQUEST)context;
PMDL mdl;
PVOID data;
PNET_BUFFER buffer;
size_t length = 0;
NTSTATUS status;
UNREFERENCED_PARAMETER(dispatch_level);
DEBUG("COMPLETE: write/inject packet complete (request=%p)", request);
buffer = NET_BUFFER_LIST_FIRST_NB(buffers);
status = NET_BUFFER_LIST_STATUS(buffers);
if (NT_SUCCESS(status))
{
length = NET_BUFFER_DATA_LENGTH(buffer);
}
else
{
DEBUG_ERROR("failed to inject packet", status);
}
mdl = NET_BUFFER_FIRST_MDL(buffer);
data = MmGetSystemAddressForMdlSafe(mdl, NormalPagePriority);
if (data != NULL)
{
ExFreePoolWithTag(data, WINDIVERT_TAG);
}
IoFreeMdl(mdl);
FwpsFreeNetBufferList0(buffers);
WdfRequestCompleteWithInformation(request, status, length);
}
/*
* WinDivert caller context preprocessing.
*/
VOID windivert_caller_context(IN WDFDEVICE device, IN WDFREQUEST request)
{
PCHAR inbuf;
size_t inbuflen;
WDF_REQUEST_PARAMETERS params;
WDFMEMORY memobj;
windivert_addr_t addr = NULL;
windivert_ioctl_t ioctl;
WDF_OBJECT_ATTRIBUTES attributes;
req_context_t req_context = NULL;
NTSTATUS status;
WDF_REQUEST_PARAMETERS_INIT(¶ms);
WdfRequestGetParameters(request, ¶ms);
if (params.Type != WdfRequestTypeDeviceControl)
{
goto windivert_caller_context_exit;
}
// Get and verify the input buffer.
status = WdfRequestRetrieveInputBuffer(request, 0, &inbuf, &inbuflen);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to retrieve input buffer", status);
goto windivert_caller_context_error;
}
if (inbuflen != sizeof(struct windivert_ioctl_s))
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("input buffer not an ioctl message header", status);
goto windivert_caller_context_error;
}
ioctl = (windivert_ioctl_t)inbuf;
if (ioctl->version != WINDIVERT_IOCTL_VERSION ||
ioctl->magic != WINDIVERT_IOCTL_MAGIC)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("input buffer contained a bad ioctl message header",
status);
goto windivert_caller_context_error;
}
// Probe and lock user buffers here (if required).
WDF_OBJECT_ATTRIBUTES_INIT_CONTEXT_TYPE(&attributes, req_context_s);
status = WdfObjectAllocateContext(request, &attributes, &req_context);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to allocate request context for ioctl", status);
goto windivert_caller_context_error;
}
req_context->addr = NULL;
if (ioctl->arg == (UINT64)NULL)
{
goto windivert_caller_context_exit;
}
switch (params.Parameters.DeviceIoControl.IoControlCode)
{
case IOCTL_WINDIVERT_RECV:
status = WdfRequestProbeAndLockUserBufferForWrite(request,
(PVOID)ioctl->arg, sizeof(struct windivert_addr_s), &memobj);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("invalid arg pointer for RECV ioctl", status);
goto windivert_caller_context_error;
}
addr = (windivert_addr_t)WdfMemoryGetBuffer(memobj, NULL);
break;
case IOCTL_WINDIVERT_SEND:
status = WdfRequestProbeAndLockUserBufferForRead(request,
(PVOID)ioctl->arg, sizeof(struct windivert_addr_s), &memobj);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("invalid arg pointer for SEND ioctl", status);
goto windivert_caller_context_error;
}
addr = (windivert_addr_t)WdfMemoryGetBuffer(memobj, NULL);
break;
case IOCTL_WINDIVERT_START_FILTER:
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("arg pointer is non-NULL for SET_FILTER ioctl",
status);
goto windivert_caller_context_error;
case IOCTL_WINDIVERT_SET_LAYER:
case IOCTL_WINDIVERT_SET_PRIORITY:
case IOCTL_WINDIVERT_SET_FLAGS:
case IOCTL_WINDIVERT_SET_PARAM:
case IOCTL_WINDIVERT_GET_PARAM:
break;
default:
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to complete I/O control; invalid request",
status);
goto windivert_caller_context_error;
}
req_context->addr = addr;
windivert_caller_context_exit:
status = WdfDeviceEnqueueRequest(device, request);
windivert_caller_context_error:
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to enqueue request", status);
WdfRequestComplete(request, status);
}
}
/*
* WinDivert I/O control.
*/
extern VOID windivert_ioctl(IN WDFQUEUE queue, IN WDFREQUEST request,
IN size_t out_length, IN size_t in_length, IN ULONG code)
{
PCHAR inbuf, outbuf;
size_t inbuflen, outbuflen, filter_len;
windivert_ioctl_t ioctl;
windivert_ioctl_filter_t filter;
windivert_addr_t addr;
req_context_t req_context;
NTSTATUS status = STATUS_SUCCESS;
context_t context =
windivert_context_get(WdfRequestGetFileObject(request));
UINT64 value, *valptr;
UNREFERENCED_PARAMETER(queue);
DEBUG("IOCTL: I/O control request (context=%p)", context);
if (!windivert_context_verify(context, WINDIVERT_CONTEXT_STATE_OPEN))
{
status = STATUS_INVALID_DEVICE_STATE;
goto windivert_ioctl_exit;
}
// Get the buffers and do sanity checks.
status = WdfRequestRetrieveInputBuffer(request, 0, &inbuf, &inbuflen);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to retrieve input buffer", status);
goto windivert_ioctl_exit;
}
switch (code)
{
case IOCTL_WINDIVERT_START_FILTER: case IOCTL_WINDIVERT_GET_PARAM:
status = WdfRequestRetrieveOutputBuffer(request, 0, &outbuf,
&outbuflen);
if (!NT_SUCCESS(status))
{
DEBUG_ERROR("failed to retrieve output buffer", status);
goto windivert_ioctl_exit;
}
break;
default:
outbuf = NULL;
outbuflen = 0;
break;
}
// Handle the ioctl:
switch (code)
{
case IOCTL_WINDIVERT_RECV:
status = windivert_read(context, request);
if (NT_SUCCESS(status))
{
return;
}
break;
case IOCTL_WINDIVERT_SEND:
req_context = windivert_req_context_get(request);
addr = req_context->addr;
status = windivert_write(context, request, addr);
if (NT_SUCCESS(status))
{
return;
}
break;
case IOCTL_WINDIVERT_START_FILTER:
{
BOOL is_inbound, is_outbound, is_ipv4, is_ipv6;
if (InterlockedExchange(&context->filter_on, TRUE) == TRUE)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("duplicate SET_FILTER ioctl", status);
goto windivert_ioctl_exit;
}
context->layer = context->layer_0;
context->flags = context->flags_0;
context->priority = context->priority_0;
filter = (windivert_ioctl_filter_t)outbuf;
filter_len = outbuflen;
context->filter = windivert_filter_compile(filter, filter_len);
if (context->filter == NULL)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to compile filter", status);
goto windivert_ioctl_exit;
}
windivert_filter_analyze(context->filter, &is_inbound,
&is_outbound, &is_ipv4, &is_ipv6);
status = windivert_register_callouts(context, is_inbound,
is_outbound, is_ipv4, is_ipv6);
// Start the timer.
WdfTimerStart(context->timer,
WDF_REL_TIMEOUT_IN_MS(context->timer_timeout));
break;
}
case IOCTL_WINDIVERT_SET_LAYER:
ioctl = (windivert_ioctl_t)inbuf;
if (ioctl->arg > WINDIVERT_LAYER_MAX)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to set layer; value too big", status);
goto windivert_ioctl_exit;
}
context->layer_0 = (UINT8)ioctl->arg;
break;
case IOCTL_WINDIVERT_SET_PRIORITY:
ioctl = (windivert_ioctl_t)inbuf;
if (ioctl->arg > WINDIVERT_PRIORITY_MAX)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to set priority; value too big", status);
goto windivert_ioctl_exit;
}
context->priority_0 = (UINT16)ioctl->arg;
break;
case IOCTL_WINDIVERT_SET_FLAGS:
ioctl = (windivert_ioctl_t)inbuf;
if (!WINDIVERT_FLAGS_VALID(ioctl->arg))
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to set flags; invalid flags value",
status);
goto windivert_ioctl_exit;
}
context->flags_0 = ioctl->arg;
break;
case IOCTL_WINDIVERT_SET_PARAM:
ioctl = (windivert_ioctl_t)inbuf;
value = ioctl->arg;
switch ((WINDIVERT_PARAM)ioctl->arg8)
{
case WINDIVERT_PARAM_QUEUE_LEN:
if (value < WINDIVERT_PARAM_QUEUE_LEN_MIN ||
value > WINDIVERT_PARAM_QUEUE_LEN_MAX)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to set queue length; invalid "
"value", status);
goto windivert_ioctl_exit;
}
context->packet_queue_maxlength = (ULONG)value;
break;
case WINDIVERT_PARAM_QUEUE_TIME:
if (value < WINDIVERT_PARAM_QUEUE_TIME_MIN ||
value > WINDIVERT_PARAM_QUEUE_TIME_MAX)
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to set queue time; invalid "
"value", status);
goto windivert_ioctl_exit;
}
context->timer_timeout = (UINT)value;
break;
default:
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to set parameter; invalid parameter",
status);
goto windivert_ioctl_exit;
}
break;
case IOCTL_WINDIVERT_GET_PARAM:
ioctl = (windivert_ioctl_t)inbuf;
if (outbuflen != sizeof(UINT64))
{
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to get parameter; invalid output "
"buffer size", status);
goto windivert_ioctl_exit;
}
valptr = (UINT64 *)outbuf;
switch ((WINDIVERT_PARAM)ioctl->arg8)
{
case WINDIVERT_PARAM_QUEUE_LEN:
*valptr = context->packet_queue_maxlength;
break;
case WINDIVERT_PARAM_QUEUE_TIME:
*valptr = context->timer_timeout;
break;
default:
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to get parameter; invalid parameter",
status);
goto windivert_ioctl_exit;
}
break;
default:
status = STATUS_INVALID_DEVICE_REQUEST;
DEBUG_ERROR("failed to complete I/O control; invalid request",
status);
break;
}
windivert_ioctl_exit:
WdfRequestComplete(request, status);
}
/*
* WinDivert notify callout.
*/
static NTSTATUS windivert_notify_callout(IN FWPS_CALLOUT_NOTIFY_TYPE type,
IN const GUID *filter_key, IN const FWPS_FILTER0 *filter)
{
UNREFERENCED_PARAMETER(type);
UNREFERENCED_PARAMETER(filter_key);
UNREFERENCED_PARAMETER(filter);
return STATUS_SUCCESS;
}
/*
* WinDivert classify outbound IPv4 callout.
*/
static void windivert_classify_outbound_network_v4_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
windivert_classify_callout(WINDIVERT_DIRECTION_OUTBOUND,
fixed_vals->incomingValue[
FWPS_FIELD_OUTBOUND_IPPACKET_V4_INTERFACE_INDEX].value.uint32,
fixed_vals->incomingValue[
FWPS_FIELD_OUTBOUND_IPPACKET_V4_SUB_INTERFACE_INDEX].value.uint32,
TRUE, fixed_vals, meta_vals, data, filter, flow_context, result);
}
/*
* WinDivert classify outbound IPv6 callout.
*/
static void windivert_classify_outbound_network_v6_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
windivert_classify_callout(WINDIVERT_DIRECTION_OUTBOUND,
fixed_vals->incomingValue[
FWPS_FIELD_OUTBOUND_IPPACKET_V6_INTERFACE_INDEX].value.uint32,
fixed_vals->incomingValue[
FWPS_FIELD_OUTBOUND_IPPACKET_V6_SUB_INTERFACE_INDEX].value.uint32,
FALSE, fixed_vals, meta_vals, data, filter, flow_context, result);
}
/*
* WinDivert classify inbound IPv4 callout.
*/
static void windivert_classify_inbound_network_v4_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
PNET_BUFFER_LIST buffers = (PNET_BUFFER_LIST)data;
PNET_BUFFER buffer;
NTSTATUS status;
if (!(result->rights & FWPS_RIGHT_ACTION_WRITE) || data == NULL)
{
return;
}
buffer = NET_BUFFER_LIST_FIRST_NB(buffers);
status = NdisRetreatNetBufferDataStart(buffer, meta_vals->ipHeaderSize,
0, NULL);
if (!NT_SUCCESS(status))
{
result->actionType = FWP_ACTION_PERMIT;
return;
}
windivert_classify_callout(WINDIVERT_DIRECTION_INBOUND,
fixed_vals->incomingValue[
FWPS_FIELD_INBOUND_IPPACKET_V4_INTERFACE_INDEX].value.uint32,
fixed_vals->incomingValue[
FWPS_FIELD_INBOUND_IPPACKET_V4_SUB_INTERFACE_INDEX].value.uint32,
TRUE, fixed_vals, meta_vals, data, filter, flow_context, result);
if (result->actionType != FWP_ACTION_BLOCK)
{
NdisAdvanceNetBufferDataStart(buffer, meta_vals->ipHeaderSize,
FALSE, NULL);
}
}
/*
* WinDivert classify inbound IPv6 callout.
*/
static void windivert_classify_inbound_network_v6_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
PNET_BUFFER_LIST buffers = (PNET_BUFFER_LIST)data;
PNET_BUFFER buffer;
NTSTATUS status;
if (!(result->rights & FWPS_RIGHT_ACTION_WRITE) || data == NULL)
{
return;
}
buffer = NET_BUFFER_LIST_FIRST_NB(buffers);
status = NdisRetreatNetBufferDataStart(buffer, sizeof(struct ipv6hdr),
0, NULL);
if (!NT_SUCCESS(status))
{
result->actionType = FWP_ACTION_PERMIT;
return;
}
windivert_classify_callout(WINDIVERT_DIRECTION_INBOUND,
fixed_vals->incomingValue[
FWPS_FIELD_INBOUND_IPPACKET_V6_INTERFACE_INDEX].value.uint32,
fixed_vals->incomingValue[
FWPS_FIELD_INBOUND_IPPACKET_V6_SUB_INTERFACE_INDEX].value.uint32,
FALSE, fixed_vals, meta_vals, data, filter, flow_context, result);
if (result->actionType != FWP_ACTION_BLOCK)
{
NdisAdvanceNetBufferDataStart(buffer, sizeof(struct ipv6hdr), FALSE,
NULL);
}
}
/*
* WinDivert classify forward IPv4 callout.
*/
static void windivert_classify_forward_network_v4_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
windivert_classify_callout(WINDIVERT_DIRECTION_OUTBOUND,
fixed_vals->incomingValue[
FWPS_FIELD_IPFORWARD_V4_DESTINATION_INTERFACE_INDEX].value.uint32,
0, TRUE, fixed_vals, meta_vals, data, filter, flow_context, result);
}
/*
* WinDivert classify forward IPv6 callout.
*/
static void windivert_classify_forward_network_v6_callout(
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
windivert_classify_callout(WINDIVERT_DIRECTION_OUTBOUND,
fixed_vals->incomingValue[
FWPS_FIELD_IPFORWARD_V6_DESTINATION_INTERFACE_INDEX].value.uint32,
0, FALSE, fixed_vals, meta_vals, data, filter, flow_context, result);
}
/*
* WinDivert classify callout.
*/
static void windivert_classify_callout(IN UINT8 direction, IN UINT32 if_idx,
IN UINT32 sub_if_idx, IN BOOL isipv4,
IN const FWPS_INCOMING_VALUES0 *fixed_vals,
IN const FWPS_INCOMING_METADATA_VALUES0 *meta_vals, IN OUT void *data,
const FWPS_FILTER0 *filter, IN UINT64 flow_context,
OUT FWPS_CLASSIFY_OUT0 *result)
{
FWPS_PACKET_INJECTION_STATE packet_state;
HANDLE packet_context;
UINT32 priority;
PNET_BUFFER_LIST buffers;
PNET_BUFFER buffer;
BOOL outbound, queued;
context_t context;
packet_t packet;
// Basic checks:
if (!(result->rights & FWPS_RIGHT_ACTION_WRITE) || data == NULL)
{
return;
}
context = (context_t)filter->context;
if (!windivert_context_verify(context, WINDIVERT_CONTEXT_STATE_OPEN))
{
result->actionType = FWP_ACTION_PERMIT;
return;
}
buffers = (PNET_BUFFER_LIST)data;
buffer = NET_BUFFER_LIST_FIRST_NB(buffers);
if (NET_BUFFER_LIST_NEXT_NBL(buffers) != NULL)
{
/*
* This is a fragment group. This can be ignored since each
* fragment should already have been indicated.
*/
result->actionType = FWP_ACTION_PERMIT;
return;
}
if (isipv4)
{
packet_state = FwpsQueryPacketInjectionState0(inject_handle, buffers,
&packet_context);
}
else
{
packet_state = FwpsQueryPacketInjectionState0(injectv6_handle,
buffers, &packet_context);
}
if (packet_state == FWPS_PACKET_INJECTED_BY_SELF ||
packet_state == FWPS_PACKET_PREVIOUSLY_INJECTED_BY_SELF)
{
priority = (UINT32)packet_context;
if (priority <= context->priority)
{
result->actionType = FWP_ACTION_PERMIT;
return;
}
}
/*
* Test if the packet matches the filter or not. If so, queue the
* packet; otherwise permit the packet.
*/
queued = FALSE;
outbound = (direction == WINDIVERT_DIRECTION_OUTBOUND);
if (windivert_filter(buffer, if_idx, sub_if_idx, outbound,
context->filter))
{
if ((context->flags & WINDIVERT_FLAG_DROP) == 0)
{
if (!windivert_queue_packet(context, buffers, buffer, direction,
if_idx, sub_if_idx))
{
goto windivert_classify_callout_exit;
}
queued = TRUE;
}
}
else
{
result->actionType = FWP_ACTION_PERMIT;
return;
}
/*
* If the packet was queued, then service any pending read.
*/
if (queued)
{
KeSetEvent(&context->read_event, IO_NO_INCREMENT, FALSE);
}
windivert_classify_callout_exit:
if ((context->flags & WINDIVERT_FLAG_SNIFF) != 0)
{
result->actionType = FWP_ACTION_PERMIT;
}
else
{
result->actionType = FWP_ACTION_BLOCK;
result->flags |= FWPS_CLASSIFY_OUT_FLAG_ABSORB;
result->rights &= ~FWPS_RIGHT_ACTION_WRITE;
}
}
/*
* Queue a NET_BUFFER.
*/
static BOOL windivert_queue_packet(context_t context, PNET_BUFFER_LIST buffers,
PNET_BUFFER buffer, UINT8 direction, UINT32 if_idx, UINT32 sub_if_idx)
{
KLOCK_QUEUE_HANDLE lock_handle;
NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO checksum_info;
PLIST_ENTRY entry;
ULONG length;
PVOID src;
packet_t packet;
NTSTATUS status;
length = NET_BUFFER_DATA_LENGTH(buffer);
packet = (packet_t)ExAllocatePoolWithTag(NonPagedPool,
WINDIVERT_PACKET_SIZE + length, WINDIVERT_TAG);
if (packet == NULL)
{
return FALSE;
}
// Copy the packet data
src = NdisGetDataBuffer(buffer, length, NULL, 1, 0);
if (src == NULL)
{
NdisGetDataBuffer(buffer, length, packet->data, 1, 0);
}
else
{
RtlCopyMemory(packet->data, src, length);
}
packet->data_len = length;
checksum_info.Value = NET_BUFFER_LIST_INFO(buffers,
TcpIpChecksumNetBufferListInfo);
packet->direction = direction;
packet->if_idx = if_idx;
packet->sub_if_idx = sub_if_idx;
if (direction == WINDIVERT_DIRECTION_OUTBOUND)
{
// IPv4 Checksum is not calculated yet
packet->ip_checksum = TRUE;
packet->tcp_checksum = (BOOL)checksum_info.Transmit.TcpChecksum;
packet->udp_checksum = (BOOL)checksum_info.Transmit.UdpChecksum;
}
else
{
packet->ip_checksum = FALSE;
packet->tcp_checksum = FALSE;
packet->udp_checksum = FALSE;
}
packet->timer_ticktock = context->timer_ticktock;
entry = &packet->entry;
KeAcquireInStackQueuedSpinLock(&context->lock, &lock_handle);
if (context->state != WINDIVERT_CONTEXT_STATE_OPEN)
{
// We are no longer open
KeReleaseInStackQueuedSpinLock(&lock_handle);
windivert_free_packet(packet);
return FALSE;
}
InsertTailList(&context->packet_queue, entry);
entry = NULL;
context->packet_queue_length++;
if (context->packet_queue_length > context->packet_queue_maxlength)
{
entry = RemoveHeadList(&context->packet_queue);
context->packet_queue_length--;
}
KeReleaseInStackQueuedSpinLock(&lock_handle);
if (entry != NULL)
{
// Queue is full; 'entry' contains a dropped packet.
DEBUG("DROP: packet queue is full, dropping packet");
packet = CONTAINING_RECORD(entry, struct packet_s, entry);
windivert_free_packet(packet);
}
DEBUG("PACKET: diverting packet (packet=%p)", packet);
return TRUE;
}
/*
* Free a packet.
*/
static void windivert_free_packet(packet_t packet)
{
ExFreePoolWithTag(packet, WINDIVERT_TAG);
}
/*
* Generic checksum calculation.
*/
static UINT16 windivert_checksum(const void *pseudo_header,
size_t pseudo_header_len, const void *data, size_t len)
{
register const UINT16 *data16 = (const UINT16 *)pseudo_header;
register size_t len16 = pseudo_header_len >> 1;
register UINT32 sum = 0;
size_t i;
for (i = 0; i < len16; i++)
{
sum += (UINT32)data16[i];
}
data16 = (const UINT16 *)data;
len16 = len >> 1;
for (i = 0; i < len16; i++)
{
sum += (UINT32)data16[i];
}
if (len & 0x1)
{
const UINT8 *data8 = (const UINT8 *)data;
sum += (UINT32)data8[len-1];
}
sum = (sum & 0xFFFF) + (sum >> 16);
sum += (sum >> 16);
sum = ~sum;
return (UINT16)sum;
}
/*
* Given a well-formed packet, update the IP and/or TCP/UDP checksums if
* required.
*/
static void windivert_update_checksums(void *header, size_t len,
BOOL update_ip, BOOL update_tcp, BOOL update_udp)
{
struct
{
UINT32 SrcAddr;
UINT32 DstAddr;
UINT8 Zero;
UINT8 Protocol;
UINT16 TransLength;
} pseudo_header;
struct iphdr *ip_header = (struct iphdr *)header;
size_t ip_header_len, trans_len;
void *trans_header;
struct tcphdr *tcp_header;
struct udphdr *udp_header;
UINT16 *trans_check_ptr;
UINT sum;
if (!update_ip && !update_tcp && !update_udp)
{
return;
}
if (len < sizeof(struct iphdr))
{
return;
}
if (ip_header->Version != 4)
{
return;
}
ip_header_len = ip_header->HdrLength*sizeof(UINT32);
if (len < ip_header_len)
{
return;
}
if (update_ip)
{
ip_header->Checksum = 0;
ip_header->Checksum = windivert_checksum(NULL, 0, ip_header,
ip_header_len);
}
trans_len = RtlUshortByteSwap(ip_header->Length) - ip_header_len;
trans_header = (UINT8 *)ip_header + ip_header_len;
switch (ip_header->Protocol)
{
case IPPROTO_TCP:
if (!update_tcp)
{
return;
}
tcp_header = (struct tcphdr *)trans_header;
if (trans_len < sizeof(struct tcphdr))
{
return;
}
trans_check_ptr = &tcp_header->Checksum;
break;
case IPPROTO_UDP:
if (!update_udp)
{
return;
}
udp_header = (struct udphdr *)trans_header;
if (trans_len < sizeof(struct udphdr))
{
return;
}
trans_check_ptr = &udp_header->Checksum;
break;
default:
return;
}
pseudo_header.SrcAddr = ip_header->SrcAddr;
pseudo_header.DstAddr = ip_header->DstAddr;
pseudo_header.Zero = 0x0;
pseudo_header.Protocol = ip_header->Protocol;
pseudo_header.TransLength = RtlUshortByteSwap((UINT16)trans_len);
*trans_check_ptr = 0x0;
sum = windivert_checksum(&pseudo_header, sizeof(pseudo_header),
trans_header, trans_len);
if (sum == 0 && ip_header->Protocol == IPPROTO_UDP)
{
*trans_check_ptr = 0xFFFF;
}
else
{
*trans_check_ptr = (UINT16)sum;
}
}
/*
* Checks if the given packet is of interest.
*/
static BOOL windivert_filter(PNET_BUFFER buffer, UINT32 if_idx,
UINT32 sub_if_idx, BOOL outbound, filter_t filter)
{
// Buffer contains enough space for a full size iphdr and tcphdr/udphdr
// (without options)
UINT8 storage[0xF*sizeof(UINT32) + sizeof(struct tcphdr)];
UINT8 *headers;
size_t tot_len, cpy_len, ip_header_len;
struct iphdr *ip_header = NULL;
struct ipv6hdr *ipv6_header = NULL;
struct icmphdr *icmp_header = NULL;
struct icmpv6hdr *icmpv6_header = NULL;
struct tcphdr *tcp_header = NULL;
struct udphdr *udp_header = NULL;
UINT16 ip, ttl;
UINT8 protocol;
// Parse the headers:
tot_len = NET_BUFFER_DATA_LENGTH(buffer);
if (tot_len < sizeof(struct iphdr))
{
DEBUG("FILTER: REJECT (packet length too small)");
return FALSE;
}
cpy_len = (tot_len < sizeof(storage)? tot_len: sizeof(storage));
headers = (UINT8 *)NdisGetDataBuffer(buffer, (ULONG)cpy_len, storage, 1,
0);
if (headers == NULL)
{
headers = storage;
}
ip_header = (struct iphdr *)headers;
switch (ip_header->Version)
{
case 4:
ip_header_len = ip_header->HdrLength*sizeof(UINT32);
if (RtlUshortByteSwap(ip_header->Length) != tot_len ||
ip_header->HdrLength < 5 ||
ip_header_len > tot_len)
{
DEBUG("FILTER: REJECT (bad IPv4 packet)");
return FALSE;
}
protocol = ip_header->Protocol;
break;
case 6:
ip_header = NULL;
ipv6_header = (struct ipv6hdr *)headers;
ip_header_len = sizeof(struct ipv6hdr);
if (ip_header_len > tot_len ||
RtlUshortByteSwap(ipv6_header->Length) +
sizeof(struct ipv6hdr) != tot_len)
{
DEBUG("FILTER: REJECT (bad IPv6 packet)");
return FALSE;
}
protocol = ipv6_header->NextHdr;
break;
default:
DEBUG("FILTER: REJECT (packet is neither IPv4 nor IPv6)");
return FALSE;
}
switch (protocol)
{
case IPPROTO_ICMP:
icmp_header = (struct icmphdr *)(headers + ip_header_len);
if (ip_header == NULL ||
sizeof(struct icmphdr) + ip_header_len > tot_len)
{
DEBUG("FILTER: REJECT (bad ICMP packet)");
return FALSE;
}
break;
case IPPROTO_ICMPV6:
icmpv6_header = (struct icmpv6hdr *)(headers + ip_header_len);
if (ipv6_header == NULL ||
sizeof(struct icmpv6hdr) + ip_header_len > tot_len)
{
DEBUG("FILTER: REJECT (bad ICMPV6 packet)");
return FALSE;
}
break;
case IPPROTO_TCP:
tcp_header = (struct tcphdr *)(headers + ip_header_len);
if (tcp_header->HdrLength < 5 ||
tcp_header->HdrLength*sizeof(UINT32) + ip_header_len > tot_len)
{
DEBUG("FILTER: REJECT (bad TCP packet)");
return FALSE;
}
break;
case IPPROTO_UDP:
udp_header = (struct udphdr *)(headers + ip_header_len);
if (sizeof(struct udphdr) + ip_header_len > tot_len)
{
DEBUG("FILTER: REJECT (bad UDP packet)");
return FALSE;
}
break;
default:
break;
}
// Execute the filter:
ip = 0;
ttl = WINDIVERT_FILTER_MAXLEN+1; // Additional safety
while (ttl-- != 0)
{
BOOL result;
UINT32 field[4];
field[1] = 0;
field[2] = 0;
field[3] = 0;
switch (filter[ip].protocol)
{
case WINDIVERT_FILTER_PROTOCOL_NONE:
result = TRUE;
break;
case WINDIVERT_FILTER_PROTOCOL_IP:
result = (ip_header != NULL);
break;
case WINDIVERT_FILTER_PROTOCOL_IPV6:
result = (ipv6_header != NULL);
break;
case WINDIVERT_FILTER_PROTOCOL_ICMP:
result = (icmp_header != NULL);
break;
case WINDIVERT_FILTER_PROTOCOL_ICMPV6:
result = (icmpv6_header != NULL);
break;
case WINDIVERT_FILTER_PROTOCOL_TCP:
result = (tcp_header != NULL);
break;
case WINDIVERT_FILTER_PROTOCOL_UDP:
result = (udp_header != NULL);
break;
default:
result = FALSE;
break;
}
if (result)
{
switch (filter[ip].field)
{
case WINDIVERT_FILTER_FIELD_ZERO:
field[0] = 0;
break;
case WINDIVERT_FILTER_FIELD_INBOUND:
field[0] = (UINT32)(!outbound);
break;
case WINDIVERT_FILTER_FIELD_OUTBOUND:
field[0] = (UINT32)outbound;
break;
case WINDIVERT_FILTER_FIELD_IFIDX:
field[0] = (UINT32)if_idx;
break;
case WINDIVERT_FILTER_FIELD_SUBIFIDX:
field[0] = (UINT32)sub_if_idx;
break;
case WINDIVERT_FILTER_FIELD_IP:
field[0] = (UINT32)(ip_header != NULL);
break;
case WINDIVERT_FILTER_FIELD_IPV6:
field[0] = (UINT32)(ipv6_header != NULL);
break;
case WINDIVERT_FILTER_FIELD_ICMP:
field[0] = (UINT32)(icmp_header != NULL);
break;
case WINDIVERT_FILTER_FIELD_ICMPV6:
field[0] = (UINT32)(icmpv6_header != NULL);
break;
case WINDIVERT_FILTER_FIELD_TCP:
field[0] = (UINT32)(tcp_header != NULL);
break;
case WINDIVERT_FILTER_FIELD_UDP:
field[0] = (UINT32)(udp_header != NULL);
break;
case WINDIVERT_FILTER_FIELD_IP_HDRLENGTH:
field[0] = (UINT32)ip_header->HdrLength;
break;
case WINDIVERT_FILTER_FIELD_IP_TOS:
field[0] = (UINT32)RtlUshortByteSwap(ip_header->TOS);
break;
case WINDIVERT_FILTER_FIELD_IP_LENGTH:
field[0] = (UINT32)RtlUshortByteSwap(ip_header->Length);
break;
case WINDIVERT_FILTER_FIELD_IP_ID:
field[0] = (UINT32)RtlUshortByteSwap(ip_header->Id);
break;
case WINDIVERT_FILTER_FIELD_IP_DF:
field[0] = (UINT32)IPHDR_GET_DF(ip_header);
break;
case WINDIVERT_FILTER_FIELD_IP_MF:
field[0] = (UINT32)IPHDR_GET_MF(ip_header);
break;
case WINDIVERT_FILTER_FIELD_IP_FRAGOFF:
field[0] = (UINT32)RtlUshortByteSwap(
IPHDR_GET_FRAGOFF(ip_header));
break;
case WINDIVERT_FILTER_FIELD_IP_TTL:
field[0] = (UINT32)ip_header->TTL;
break;
case WINDIVERT_FILTER_FIELD_IP_PROTOCOL:
field[0] = (UINT32)ip_header->Protocol;
break;
case WINDIVERT_FILTER_FIELD_IP_CHECKSUM:
field[0] = (UINT32)RtlUshortByteSwap(ip_header->Checksum);
break;
case WINDIVERT_FILTER_FIELD_IP_SRCADDR:
field[0] = (UINT32)RtlUlongByteSwap(ip_header->SrcAddr);
break;
case WINDIVERT_FILTER_FIELD_IP_DSTADDR:
field[0] = (UINT32)RtlUlongByteSwap(ip_header->DstAddr);
break;
case WINDIVERT_FILTER_FIELD_IPV6_TRAFFICCLASS:
field[0] = (UINT32)IPV6HDR_GET_TRAFFICCLASS(ipv6_header);
break;
case WINDIVERT_FILTER_FIELD_IPV6_FLOWLABEL:
field[0] = (UINT32)RtlUlongByteSwap(
IPV6HDR_GET_FLOWLABEL(ipv6_header));
break;
case WINDIVERT_FILTER_FIELD_IPV6_LENGTH:
field[0] = (UINT32)RtlUshortByteSwap(ipv6_header->Length);
break;
case WINDIVERT_FILTER_FIELD_IPV6_NEXTHDR:
field[0] = (UINT32)ipv6_header->NextHdr;
break;
case WINDIVERT_FILTER_FIELD_IPV6_HOPLIMIT:
field[0] = (UINT32)ipv6_header->HopLimit;
break;
case WINDIVERT_FILTER_FIELD_IPV6_SRCADDR:
field[0] =
(UINT32)RtlUlongByteSwap(ipv6_header->SrcAddr[3]);
field[1] =
(UINT32)RtlUlongByteSwap(ipv6_header->SrcAddr[2]);
field[2] =
(UINT32)RtlUlongByteSwap(ipv6_header->SrcAddr[1]);
field[3] =
(UINT32)RtlUlongByteSwap(ipv6_header->SrcAddr[0]);
break;
case WINDIVERT_FILTER_FIELD_IPV6_DSTADDR:
field[0] =
(UINT32)RtlUlongByteSwap(ipv6_header->DstAddr[3]);
field[1] =
(UINT32)RtlUlongByteSwap(ipv6_header->DstAddr[2]);
field[2] =
(UINT32)RtlUlongByteSwap(ipv6_header->DstAddr[1]);
field[3] =
(UINT32)RtlUlongByteSwap(ipv6_header->DstAddr[0]);
break;
case WINDIVERT_FILTER_FIELD_ICMP_TYPE:
field[0] = (UINT32)icmp_header->Type;
break;
case WINDIVERT_FILTER_FIELD_ICMP_CODE:
field[0] = (UINT32)icmp_header->Code;
break;
case WINDIVERT_FILTER_FIELD_ICMP_CHECKSUM:
field[0] =
(UINT32)RtlUshortByteSwap(icmp_header->Checksum);
break;
case WINDIVERT_FILTER_FIELD_ICMP_BODY:
field[0] = (UINT32)RtlUlongByteSwap(icmp_header->Body);
break;
case WINDIVERT_FILTER_FIELD_ICMPV6_TYPE:
field[0] = (UINT32)icmpv6_header->Type;
break;
case WINDIVERT_FILTER_FIELD_ICMPV6_CODE:
field[0] = (UINT32)icmpv6_header->Code;
break;
case WINDIVERT_FILTER_FIELD_ICMPV6_CHECKSUM:
field[0] = (UINT32)icmpv6_header->Checksum;
break;
case WINDIVERT_FILTER_FIELD_ICMPV6_BODY:
field[0] = (UINT32)icmpv6_header->Body;
break;
case WINDIVERT_FILTER_FIELD_TCP_SRCPORT:
field[0] = (UINT32)RtlUshortByteSwap(tcp_header->SrcPort);
break;
case WINDIVERT_FILTER_FIELD_TCP_DSTPORT:
field[0] = (UINT32)RtlUshortByteSwap(tcp_header->DstPort);
break;
case WINDIVERT_FILTER_FIELD_TCP_SEQNUM:
field[0] = (UINT32)RtlUlongByteSwap(tcp_header->SeqNum);
break;
case WINDIVERT_FILTER_FIELD_TCP_ACKNUM:
field[0] = (UINT32)RtlUlongByteSwap(tcp_header->AckNum);
break;
case WINDIVERT_FILTER_FIELD_TCP_HDRLENGTH:
field[0] = (UINT32)tcp_header->HdrLength;
break;
case WINDIVERT_FILTER_FIELD_TCP_URG:
field[0] = (UINT32)tcp_header->Urg;
break;
case WINDIVERT_FILTER_FIELD_TCP_ACK:
field[0] = (UINT32)tcp_header->Ack;
break;
case WINDIVERT_FILTER_FIELD_TCP_PSH:
field[0] = (UINT32)tcp_header->Psh;
break;
case WINDIVERT_FILTER_FIELD_TCP_RST:
field[0] = (UINT32)tcp_header->Rst;
break;
case WINDIVERT_FILTER_FIELD_TCP_SYN:
field[0] = (UINT32)tcp_header->Syn;
break;
case WINDIVERT_FILTER_FIELD_TCP_FIN:
field[0] = (UINT32)tcp_header->Fin;
break;
case WINDIVERT_FILTER_FIELD_TCP_WINDOW:
field[0] = (UINT32)RtlUshortByteSwap(tcp_header->Window);
break;
case WINDIVERT_FILTER_FIELD_TCP_CHECKSUM:
field[0] = (UINT32)RtlUshortByteSwap(tcp_header->Checksum);
break;
case WINDIVERT_FILTER_FIELD_TCP_URGPTR:
field[0] = (UINT32)RtlUshortByteSwap(tcp_header->UrgPtr);
break;
case WINDIVERT_FILTER_FIELD_TCP_PAYLOADLENGTH:
field[0] = (UINT32)(tot_len - ip_header_len -
tcp_header->HdrLength*sizeof(UINT32));
break;
case WINDIVERT_FILTER_FIELD_UDP_SRCPORT:
field[0] = (UINT32)RtlUshortByteSwap(udp_header->SrcPort);
break;
case WINDIVERT_FILTER_FIELD_UDP_DSTPORT:
field[0] = (UINT32)RtlUshortByteSwap(udp_header->DstPort);
break;
case WINDIVERT_FILTER_FIELD_UDP_LENGTH:
field[0] = (UINT32)RtlUshortByteSwap(udp_header->Length);
break;
case WINDIVERT_FILTER_FIELD_UDP_CHECKSUM:
field[0] = (UINT32)RtlUshortByteSwap(udp_header->Checksum);
break;
case WINDIVERT_FILTER_FIELD_UDP_PAYLOADLENGTH:
field[0] = (UINT32)(tot_len - ip_header_len -
sizeof(struct udphdr));
break;
default:
field[0] = 0;
break;
}
switch (filter[ip].test)
{
case WINDIVERT_FILTER_TEST_EQ:
result = (field[0] == filter[ip].arg[0] &&
field[1] == filter[ip].arg[1] &&
field[2] == filter[ip].arg[2] &&
field[3] == filter[ip].arg[3]);
break;
case WINDIVERT_FILTER_TEST_NEQ:
result = (field[0] != filter[ip].arg[0] ||
field[1] != filter[ip].arg[1] ||
field[2] != filter[ip].arg[2] ||
field[3] != filter[ip].arg[3]);
break;
case WINDIVERT_FILTER_TEST_LT:
result = (field[3] < filter[ip].arg[3] ||
(field[3] == filter[ip].arg[3] &&
field[2] < filter[ip].arg[2] ||
(field[2] == filter[ip].arg[2] &&
field[1] < filter[ip].arg[1] ||
(field[1] == filter[ip].arg[1] &&
field[0] < filter[ip].arg[0]))));
break;
case WINDIVERT_FILTER_TEST_LEQ:
result = (field[3] < filter[ip].arg[3] ||
(field[3] == filter[ip].arg[3] &&
field[2] < filter[ip].arg[2] ||
(field[2] == filter[ip].arg[2] &&
field[1] < filter[ip].arg[1] ||
(field[1] == filter[ip].arg[1] &&
field[0] <= filter[ip].arg[0]))));
break;
case WINDIVERT_FILTER_TEST_GT:
result = (field[3] > filter[ip].arg[3] ||
(field[3] == filter[ip].arg[3] &&
field[2] > filter[ip].arg[2] ||
(field[2] == filter[ip].arg[2] &&
field[1] > filter[ip].arg[1] ||
(field[1] == filter[ip].arg[1] &&
field[0] > filter[ip].arg[0]))));
break;
case WINDIVERT_FILTER_TEST_GEQ:
result = (field[3] > filter[ip].arg[3] ||
(field[3] == filter[ip].arg[3] &&
field[2] > filter[ip].arg[2] ||
(field[2] == filter[ip].arg[2] &&
field[1] > filter[ip].arg[1] ||
(field[1] == filter[ip].arg[1] &&
field[0] >= filter[ip].arg[0]))));
break;
default:
result = FALSE;
break;
}
}
ip = (result? filter[ip].success: filter[ip].failure);
if (ip == WINDIVERT_FILTER_RESULT_ACCEPT)
{
return TRUE;
}
if (ip == WINDIVERT_FILTER_RESULT_REJECT)
{
return FALSE;
}
}
DEBUG("FILTER: REJECT (filter TTL exceeded)");
return FALSE;
}
/*
* Analyze the given filter.
*/
static void windivert_filter_analyze(filter_t filter, BOOL *is_inbound,
BOOL *is_outbound, BOOL *is_ipv4, BOOL *is_ipv6)
{
BOOL result;
// False filter?
result = windivert_filter_test(filter, 0, WINDIVERT_FILTER_PROTOCOL_NONE,
WINDIVERT_FILTER_FIELD_ZERO, 0);
if (!result)
{
*is_inbound = FALSE;
*is_outbound = FALSE;
*is_ipv4 = FALSE;
*is_ipv6 = FALSE;
return;
}
// Inbound?
result = windivert_filter_test(filter, 0, WINDIVERT_FILTER_PROTOCOL_NONE,
WINDIVERT_FILTER_FIELD_INBOUND, 1);
if (result)
{
result = windivert_filter_test(filter, 0,
WINDIVERT_FILTER_PROTOCOL_NONE, WINDIVERT_FILTER_FIELD_OUTBOUND,
0);
}
*is_inbound = result;
// Outbound?
result = windivert_filter_test(filter, 0, WINDIVERT_FILTER_PROTOCOL_NONE,
WINDIVERT_FILTER_FIELD_OUTBOUND, 1);
if (result)
{
result = windivert_filter_test(filter, 0,
WINDIVERT_FILTER_PROTOCOL_NONE, WINDIVERT_FILTER_FIELD_INBOUND, 0);
}
*is_outbound = result;
// IPv4?
result = windivert_filter_test(filter, 0, WINDIVERT_FILTER_PROTOCOL_NONE,
WINDIVERT_FILTER_FIELD_IP, 1);
if (result)
{
result = windivert_filter_test(filter, 0,
WINDIVERT_FILTER_PROTOCOL_NONE, WINDIVERT_FILTER_FIELD_IPV6, 0);
}
*is_ipv4 = result;
// Ipv6?
result = windivert_filter_test(filter, 0, WINDIVERT_FILTER_PROTOCOL_NONE,
WINDIVERT_FILTER_FIELD_IPV6, 1);
if (result)
{
result = windivert_filter_test(filter, 0,
WINDIVERT_FILTER_PROTOCOL_NONE, WINDIVERT_FILTER_FIELD_IP, 0);
}
*is_ipv6 = result;
}
/*
* Test a filter for any packet where field = arg.
*/
static BOOL windivert_filter_test(filter_t filter, UINT16 ip, UINT8 protocol,
UINT8 field, UINT32 arg)
{
BOOL known = FALSE;
BOOL result = FALSE;
if (ip == WINDIVERT_FILTER_RESULT_ACCEPT)
{
return TRUE;
}
if (ip == WINDIVERT_FILTER_RESULT_REJECT)
{
return FALSE;
}
if (ip > WINDIVERT_FILTER_MAXLEN)
{
return FALSE;
}
if (filter[ip].protocol == protocol &&
filter[ip].field == field)
{
known = TRUE;
switch (filter[ip].test)
{
case WINDIVERT_FILTER_TEST_EQ:
result = (arg == filter[ip].arg[0]);
break;
case WINDIVERT_FILTER_TEST_NEQ:
result = (arg != filter[ip].arg[0]);
break;
case WINDIVERT_FILTER_TEST_LT:
result = (arg < filter[ip].arg[0]);
break;
case WINDIVERT_FILTER_TEST_LEQ:
result = (arg <= filter[ip].arg[0]);
break;
case WINDIVERT_FILTER_TEST_GT:
result = (arg > filter[ip].arg[0]);
break;
case WINDIVERT_FILTER_TEST_GEQ:
result = (arg >= filter[ip].arg[0]);
break;
default:
result = FALSE;
break;
}
}
if (!known)
{
result = windivert_filter_test(filter, filter[ip].success, protocol,
field, arg);
if (result)
{
return TRUE;
}
return windivert_filter_test(filter, filter[ip].failure, protocol,
field, arg);
}
else
{
ip = (result? filter[ip].success: filter[ip].failure);
return windivert_filter_test(filter, ip, protocol, field, arg);
}
}
/*
* Compile a WinDivert filter from an IOCTL.
*/
static filter_t windivert_filter_compile(windivert_ioctl_filter_t ioctl_filter,
size_t ioctl_filter_len)
{
filter_t filter0 = NULL, result = NULL;
UINT16 i;
size_t length;
if (ioctl_filter_len % sizeof(struct windivert_ioctl_filter_s) != 0)
{
goto windivert_filter_compile_exit;
}
length = ioctl_filter_len / sizeof(struct windivert_ioctl_filter_s);
if (length >= WINDIVERT_FILTER_MAXLEN)
{
goto windivert_filter_compile_exit;
}
// Do NOT use the stack (size = 12Kb on x86) for filter0.
filter0 = (filter_t)ExAllocatePoolWithTag(NonPagedPool,
WINDIVERT_FILTER_MAXLEN*sizeof(struct filter_s), WINDIVERT_TAG);
if (filter0 == NULL)
{
goto windivert_filter_compile_exit;
}
for (i = 0; i < length; i++)
{
if (ioctl_filter[i].field > WINDIVERT_FILTER_FIELD_MAX ||
ioctl_filter[i].test > WINDIVERT_FILTER_TEST_MAX)
{
goto windivert_filter_compile_exit;
}
switch (ioctl_filter[i].success)
{
case WINDIVERT_FILTER_RESULT_ACCEPT:
case WINDIVERT_FILTER_RESULT_REJECT:
break;
default:
if (ioctl_filter[i].success <= i ||
ioctl_filter[i].success >= length)
{
goto windivert_filter_compile_exit;
}
break;
}
switch (ioctl_filter[i].failure)
{
case WINDIVERT_FILTER_RESULT_ACCEPT:
case WINDIVERT_FILTER_RESULT_REJECT:
break;
default:
if (ioctl_filter[i].failure <= i ||
ioctl_filter[i].failure >= length)
{
goto windivert_filter_compile_exit;
}
break;
}
// Enforce size limits:
if (ioctl_filter[i].field != WINDIVERT_FILTER_FIELD_IPV6_SRCADDR &&
ioctl_filter[i].field != WINDIVERT_FILTER_FIELD_IPV6_DSTADDR)
{
if (ioctl_filter[i].arg[1] != 0 ||
ioctl_filter[i].arg[2] != 0 ||
ioctl_filter[i].arg[3] != 0)
{
goto windivert_filter_compile_exit;
}
}
switch (ioctl_filter[i].field)
{
case WINDIVERT_FILTER_FIELD_ZERO:
case WINDIVERT_FILTER_FIELD_INBOUND:
case WINDIVERT_FILTER_FIELD_OUTBOUND:
case WINDIVERT_FILTER_FIELD_IP:
case WINDIVERT_FILTER_FIELD_IPV6:
case WINDIVERT_FILTER_FIELD_ICMP:
case WINDIVERT_FILTER_FIELD_ICMPV6:
case WINDIVERT_FILTER_FIELD_TCP:
case WINDIVERT_FILTER_FIELD_UDP:
case WINDIVERT_FILTER_FIELD_IP_DF:
case WINDIVERT_FILTER_FIELD_IP_MF:
case WINDIVERT_FILTER_FIELD_TCP_URG:
case WINDIVERT_FILTER_FIELD_TCP_ACK:
case WINDIVERT_FILTER_FIELD_TCP_PSH:
case WINDIVERT_FILTER_FIELD_TCP_RST:
case WINDIVERT_FILTER_FIELD_TCP_SYN:
case WINDIVERT_FILTER_FIELD_TCP_FIN:
if (ioctl_filter[i].arg[0] > 1)
{
goto windivert_filter_compile_exit;
}
break;
case WINDIVERT_FILTER_FIELD_IP_HDRLENGTH:
case WINDIVERT_FILTER_FIELD_TCP_HDRLENGTH:
if (ioctl_filter[i].arg[0] > 0x0F)
{
goto windivert_filter_compile_exit;
}
break;
case WINDIVERT_FILTER_FIELD_IP_TTL:
case WINDIVERT_FILTER_FIELD_IP_PROTOCOL:
case WINDIVERT_FILTER_FIELD_IPV6_TRAFFICCLASS:
case WINDIVERT_FILTER_FIELD_IPV6_NEXTHDR:
case WINDIVERT_FILTER_FIELD_IPV6_HOPLIMIT:
case WINDIVERT_FILTER_FIELD_ICMP_TYPE:
case WINDIVERT_FILTER_FIELD_ICMP_CODE:
case WINDIVERT_FILTER_FIELD_ICMPV6_TYPE:
case WINDIVERT_FILTER_FIELD_ICMPV6_CODE:
if (ioctl_filter[i].arg[0] > UINT8_MAX)
{
goto windivert_filter_compile_exit;
}
break;
case WINDIVERT_FILTER_FIELD_IP_FRAGOFF:
if (ioctl_filter[i].arg[0] > 0x1FFF)
{
goto windivert_filter_compile_exit;
}
break;
case WINDIVERT_FILTER_FIELD_IP_TOS:
case WINDIVERT_FILTER_FIELD_IP_LENGTH:
case WINDIVERT_FILTER_FIELD_IP_ID:
case WINDIVERT_FILTER_FIELD_IP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_IPV6_LENGTH:
case WINDIVERT_FILTER_FIELD_ICMP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_ICMPV6_CHECKSUM:
case WINDIVERT_FILTER_FIELD_TCP_SRCPORT:
case WINDIVERT_FILTER_FIELD_TCP_DSTPORT:
case WINDIVERT_FILTER_FIELD_TCP_WINDOW:
case WINDIVERT_FILTER_FIELD_TCP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_TCP_URGPTR:
case WINDIVERT_FILTER_FIELD_TCP_PAYLOADLENGTH:
case WINDIVERT_FILTER_FIELD_UDP_SRCPORT:
case WINDIVERT_FILTER_FIELD_UDP_DSTPORT:
case WINDIVERT_FILTER_FIELD_UDP_LENGTH:
case WINDIVERT_FILTER_FIELD_UDP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_UDP_PAYLOADLENGTH:
if (ioctl_filter[i].arg[0] > UINT16_MAX)
{
goto windivert_filter_compile_exit;
}
break;
case WINDIVERT_FILTER_FIELD_IPV6_FLOWLABEL:
if (ioctl_filter[i].arg[0] > 0x000FFFFF)
{
goto windivert_filter_compile_exit;
}
break;
default:
break;
}
filter0[i].field = ioctl_filter[i].field;
filter0[i].test = ioctl_filter[i].test;
filter0[i].success = ioctl_filter[i].success;
filter0[i].failure = ioctl_filter[i].failure;
filter0[i].arg[0] = ioctl_filter[i].arg[0];
filter0[i].arg[1] = ioctl_filter[i].arg[1];
filter0[i].arg[2] = ioctl_filter[i].arg[2];
filter0[i].arg[3] = ioctl_filter[i].arg[3];
// Protocol selection:
switch (ioctl_filter[i].field)
{
case WINDIVERT_FILTER_FIELD_ZERO:
case WINDIVERT_FILTER_FIELD_INBOUND:
case WINDIVERT_FILTER_FIELD_OUTBOUND:
case WINDIVERT_FILTER_FIELD_IFIDX:
case WINDIVERT_FILTER_FIELD_SUBIFIDX:
case WINDIVERT_FILTER_FIELD_IP:
case WINDIVERT_FILTER_FIELD_IPV6:
case WINDIVERT_FILTER_FIELD_ICMP:
case WINDIVERT_FILTER_FIELD_ICMPV6:
case WINDIVERT_FILTER_FIELD_TCP:
case WINDIVERT_FILTER_FIELD_UDP:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_NONE;
break;
case WINDIVERT_FILTER_FIELD_IP_HDRLENGTH:
case WINDIVERT_FILTER_FIELD_IP_TOS:
case WINDIVERT_FILTER_FIELD_IP_LENGTH:
case WINDIVERT_FILTER_FIELD_IP_ID:
case WINDIVERT_FILTER_FIELD_IP_DF:
case WINDIVERT_FILTER_FIELD_IP_MF:
case WINDIVERT_FILTER_FIELD_IP_FRAGOFF:
case WINDIVERT_FILTER_FIELD_IP_TTL:
case WINDIVERT_FILTER_FIELD_IP_PROTOCOL:
case WINDIVERT_FILTER_FIELD_IP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_IP_SRCADDR:
case WINDIVERT_FILTER_FIELD_IP_DSTADDR:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_IP;
break;
case WINDIVERT_FILTER_FIELD_IPV6_TRAFFICCLASS:
case WINDIVERT_FILTER_FIELD_IPV6_FLOWLABEL:
case WINDIVERT_FILTER_FIELD_IPV6_LENGTH:
case WINDIVERT_FILTER_FIELD_IPV6_NEXTHDR:
case WINDIVERT_FILTER_FIELD_IPV6_HOPLIMIT:
case WINDIVERT_FILTER_FIELD_IPV6_SRCADDR:
case WINDIVERT_FILTER_FIELD_IPV6_DSTADDR:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_IPV6;
break;
case WINDIVERT_FILTER_FIELD_ICMP_TYPE:
case WINDIVERT_FILTER_FIELD_ICMP_CODE:
case WINDIVERT_FILTER_FIELD_ICMP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_ICMP_BODY:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_ICMP;
break;
case WINDIVERT_FILTER_FIELD_ICMPV6_TYPE:
case WINDIVERT_FILTER_FIELD_ICMPV6_CODE:
case WINDIVERT_FILTER_FIELD_ICMPV6_CHECKSUM:
case WINDIVERT_FILTER_FIELD_ICMPV6_BODY:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_ICMPV6;
break;
case WINDIVERT_FILTER_FIELD_TCP_SRCPORT:
case WINDIVERT_FILTER_FIELD_TCP_DSTPORT:
case WINDIVERT_FILTER_FIELD_TCP_SEQNUM:
case WINDIVERT_FILTER_FIELD_TCP_ACKNUM:
case WINDIVERT_FILTER_FIELD_TCP_HDRLENGTH:
case WINDIVERT_FILTER_FIELD_TCP_URG:
case WINDIVERT_FILTER_FIELD_TCP_ACK:
case WINDIVERT_FILTER_FIELD_TCP_PSH:
case WINDIVERT_FILTER_FIELD_TCP_RST:
case WINDIVERT_FILTER_FIELD_TCP_SYN:
case WINDIVERT_FILTER_FIELD_TCP_FIN:
case WINDIVERT_FILTER_FIELD_TCP_WINDOW:
case WINDIVERT_FILTER_FIELD_TCP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_TCP_URGPTR:
case WINDIVERT_FILTER_FIELD_TCP_PAYLOADLENGTH:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_TCP;
break;
case WINDIVERT_FILTER_FIELD_UDP_SRCPORT:
case WINDIVERT_FILTER_FIELD_UDP_DSTPORT:
case WINDIVERT_FILTER_FIELD_UDP_LENGTH:
case WINDIVERT_FILTER_FIELD_UDP_CHECKSUM:
case WINDIVERT_FILTER_FIELD_UDP_PAYLOADLENGTH:
filter0[i].protocol = WINDIVERT_FILTER_PROTOCOL_UDP;
break;
default:
goto windivert_filter_compile_exit;
}
}
result = (filter_t)ExAllocatePoolWithTag(NonPagedPool,
i*sizeof(struct filter_s), WINDIVERT_TAG);
if (result != NULL)
{
RtlMoveMemory(result, filter0, i*sizeof(struct filter_s));
}
windivert_filter_compile_exit:
if (filter0 != NULL)
{
ExFreePoolWithTag(filter0, WINDIVERT_TAG);
}
return result;
}