Max/basil00_WinDivert
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 21 Wiki Activity

- Fix bug (see issue #14) where some outbound TCP packets were never handled

Browse Source 
by the classify function and silently dropped.  This can degrade outbound
  speed significantly, as it forces the Windows TCP/IP stack to re-send the
  missing data.  Thanks to GhalemB who found the bug & fix.
This commit is contained in:
basil00
2014-03-23 11:18:05 +08:00
parent 33f6bec1e5
commit 7f0e697092
1 changed files with 213 additions and 75 deletions
Download Patch File Download Diff File Expand all files Collapse all files
sys/windivert.c
+213 -75
View File
@@ -197,7 +197,6 @@ struct packet_s
{
LIST_ENTRY entry; // Entry for queue.
PNET_BUFFER_LIST net_buffer_list; // Clone of the net buffer list.
PVOID data; // Copy of the packet data.
size_t data_len; // Length of `data'.
UINT8 direction; // Packet direction.
UINT32 if_idx; // Interface index.
@@ -206,6 +205,7 @@ struct packet_s
BOOL tcp_checksum; // TCP checksum is valid.
BOOL udp_checksum; // UDP checksum is valid.
BOOL timer_ticktock; // Time-out ticktock.
char data[]; // Packet data.
};
typedef struct packet_s *packet_t;
@@ -395,8 +395,14 @@ static void windivert_classify_callout(IN UINT8 direction, IN UINT32 if_idx,
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,
UINT8 direction, UINT32 if_idx, UINT32 sub_if_idx);
static BOOL windivert_queue_packet(context_t context, PNET_BUFFER buffer,
PNET_BUFFER_LIST buffers, UINT8 direction, UINT32 if_idx,
UINT32 sub_if_idx);
static BOOL windivert_reinject_packet(context_t context, UINT8 direction,
BOOL isipv4, UINT32 if_idx, UINT32 sub_if_idx, UINT32 priority,
PNET_BUFFER buffer);
static void NTAPI windivert_reinject_complete(VOID *context,
NET_BUFFER_LIST *buffers, BOOLEAN dispatch_level);
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);
@@ -1327,28 +1333,10 @@ static void windivert_read_service(context_t context)
goto windivert_read_service_complete;
}
dst_len = MmGetMdlByteCount(dst_mdl);
if (packet->net_buffer_list != NULL)
{
buffer = NET_BUFFER_LIST_FIRST_NB(packet->net_buffer_list);
src_len = NET_BUFFER_DATA_LENGTH(buffer);
dst_len = (src_len < dst_len? src_len: dst_len);
src = NdisGetDataBuffer(buffer, dst_len, NULL, 1, 0);
if (src == NULL)
{
NdisGetDataBuffer(buffer, dst_len, dst, 1, 0);
}
else
{
RtlCopyMemory(dst, src, dst_len);
}
}
else
{
src_len = packet->data_len;
dst_len = (src_len < dst_len? src_len: dst_len);
src = packet->data;
RtlCopyMemory(dst, src, dst_len);
}
src_len = packet->data_len;
dst_len = (src_len < dst_len? src_len: dst_len);
src = packet->data;
RtlCopyMemory(dst, src, dst_len);
// Write the address information.
req_context = windivert_req_context_get(request);
@@ -2085,7 +2073,7 @@ static void windivert_classify_callout(IN UINT8 direction, IN UINT32 if_idx,
HANDLE packet_context;
UINT32 priority;
PNET_BUFFER_LIST buffers;
PNET_BUFFER buffer;
PNET_BUFFER buffer, buffer_fst, buffer_itr;
BOOL outbound, queued;
context_t context;
packet_t packet;
@@ -2136,28 +2124,91 @@ static void windivert_classify_callout(IN UINT8 direction, IN UINT32 if_idx,
}
/*
* Test if the packet matches the filter or not. If so, queue the
* packet; otherwise permit the packet.
* This code is complicated by the fact the a single NET_BUFFER_LIST
* may contain several NET_BUFFER structures. Each NET_BUFFER needs to
* be filtered independently. To achieve this we do the following:
* 1) First check if any NET_BUFFER passes the filter.
* 2) If no, then CONTINUE the entire NET_BUFFER_LIST.
* 3) Else, split the NET_BUFFER_LIST into individual NET_BUFFERs; and
* either queue or re-inject based on the filter.
*/
queued = FALSE;
// Find the first NET_BUFFER we need to queue:
buffer_fst = buffer;
outbound = (direction == WINDIVERT_DIRECTION_OUTBOUND);
if (windivert_filter(buffer, if_idx, sub_if_idx, outbound,
context->filter))
do
{
if ((context->flags & WINDIVERT_FLAG_DROP) == 0)
if (windivert_filter(buffer_fst, if_idx, sub_if_idx, outbound,
context->filter))
{
if (!windivert_queue_packet(context, buffers, direction, if_idx,
sub_if_idx))
break;
}
buffer_fst = NET_BUFFER_NEXT_NB(buffer_fst);
}
while (buffer_fst != NULL);
if (buffer_fst == NULL)
{
result->actionType = FWP_ACTION_CONTINUE;
return;
}
if ((context->flags & WINDIVERT_FLAG_SNIFF) == 0)
{
// Re-inject all packets up to 'buffer_fst'
buffer_itr = buffer;
while (buffer_itr != buffer_fst)
{
if (!windivert_reinject_packet(context, direction, isipv4, if_idx,
sub_if_idx, priority, buffer_itr))
{
goto windivert_classify_callout_exit;
}
queued = TRUE;
buffer_itr = NET_BUFFER_NEXT_NB(buffer_itr);
}
}
else
{
result->actionType = FWP_ACTION_CONTINUE;
return;
buffer_itr = buffer_fst;
}
queued = FALSE;
if ((context->flags & WINDIVERT_FLAG_DROP) == 0)
{
if (!windivert_queue_packet(context, buffer_itr, buffers, direction,
if_idx, sub_if_idx))
{
goto windivert_classify_callout_exit;
}
queued = TRUE;
}
// Queue or re-inject remaining packets.
buffer_itr = NET_BUFFER_NEXT_NB(buffer_itr);
while (buffer_itr != NULL)
{
if (windivert_filter(buffer_itr, if_idx, sub_if_idx, outbound,
context->filter))
{
if ((context->flags & WINDIVERT_FLAG_DROP) == 0)
{
if (!windivert_queue_packet(context, buffer_itr, buffers,
direction, if_idx, sub_if_idx))
{
goto windivert_classify_callout_exit;
}
queued = TRUE;
}
}
else if ((context->flags & WINDIVERT_FLAG_SNIFF) == 0)
{
if (!windivert_reinject_packet(context, direction, isipv4, if_idx,
sub_if_idx, priority, buffer_itr))
{
goto windivert_classify_callout_exit;
}
}
buffer_itr = NET_BUFFER_NEXT_NB(buffer_itr);
}
/*
@@ -2199,58 +2250,35 @@ windivert_classify_callout_exit:
/*
* Queue a NET_BUFFER.
*/
static BOOL windivert_queue_packet(context_t context, PNET_BUFFER_LIST buffers,
UINT8 direction, UINT32 if_idx, UINT32 sub_if_idx)
static BOOL windivert_queue_packet(context_t context, PNET_BUFFER buffer,
PNET_BUFFER_LIST buffers, UINT8 direction, UINT32 if_idx,
UINT32 sub_if_idx)
{
KLOCK_QUEUE_HANDLE lock_handle;
NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO checksum_info;
PNET_BUFFER buffer;
PVOID data;
PLIST_ENTRY entry;
packet_t packet;
UINT data_len;
NTSTATUS status;
data_len = NET_BUFFER_DATA_LENGTH(buffer);
packet = (packet_t)ExAllocatePoolWithTag(NonPagedPool,
WINDIVERT_PACKET_SIZE, WINDIVERT_TAG);
WINDIVERT_PACKET_SIZE + data_len, WINDIVERT_TAG);
if (packet == NULL)
{
return FALSE;
}
packet->net_buffer_list = NULL;
packet->data = NULL;
packet->data_len = 0;
if ((context->flags & WINDIVERT_FLAG_SNIFF) != 0)
packet->data_len = data_len;
data = NdisGetDataBuffer(buffer, data_len, NULL, 1, 0);
if (data == NULL)
{
// Deep copy for sniff-mode:
buffer = NET_BUFFER_LIST_FIRST_NB(buffers);
packet->data_len = NET_BUFFER_DATA_LENGTH(buffer);
packet->data = ExAllocatePoolWithTag(NonPagedPool,
packet->data_len, WINDIVERT_TAG);
if (packet->data == NULL)
{
ExFreePoolWithTag(packet, WINDIVERT_TAG);
return FALSE;
}
data = NdisGetDataBuffer(buffer, packet->data_len, NULL, 1, 0);
if (data == NULL)
{
NdisGetDataBuffer(buffer, packet->data_len, packet->data, 1, 0);
}
else
{
RtlCopyMemory(packet->data, data, packet->data_len);
}
NdisGetDataBuffer(buffer, data_len, packet->data, 1, 0);
}
else
{
// Shallow copy for divert-mode:
status = FwpsAllocateCloneNetBufferList0(buffers, pool_handle, NULL,
0, &packet->net_buffer_list);
if (!NT_SUCCESS(status))
{
ExFreePoolWithTag(packet, WINDIVERT_TAG);
return FALSE;
}
RtlCopyMemory(packet->data, data, data_len);
}
checksum_info.Value = NET_BUFFER_LIST_INFO(buffers,
@@ -2302,6 +2330,120 @@ static BOOL windivert_queue_packet(context_t context, PNET_BUFFER_LIST buffers,
return TRUE;
}
/*
* Re-inject a NET_BUFFER.
*/
static BOOL windivert_reinject_packet(context_t context, UINT8 direction,
BOOL isipv4, UINT32 if_idx, UINT32 sub_if_idx, UINT32 priority,
PNET_BUFFER buffer)
{
UINT data_len;
PVOID data, data_copy = NULL;
PNET_BUFFER_LIST buffers = NULL;
PMDL mdl_copy = NULL;
HANDLE handle;
NTSTATUS status = STATUS_SUCCESS;
data_len = NET_BUFFER_DATA_LENGTH(buffer);
data_copy = ExAllocatePoolWithTag(NonPagedPool, data_len, WINDIVERT_TAG);
if (data_copy == NULL)
{
status = STATUS_INSUFFICIENT_RESOURCES;
DEBUG_ERROR("failed to allocate memory for (re)injected packet data",
status);
return FALSE;
}
data = NdisGetDataBuffer(buffer, data_len, NULL, 1, 0);
if (data == NULL)
{
NdisGetDataBuffer(buffer, data_len, data_copy, 1, 0);
}
else
{
RtlCopyMemory(data_copy, data, data_len);
}
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_reinject_packet_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_reinject_packet_exit;
}
handle = (isipv4? inject_handle: injectv6_handle);
if (context->layer == WINDIVERT_LAYER_NETWORK_FORWARD)
{
status = FwpsInjectForwardAsync0(handle, (HANDLE)priority, 0,
(isipv4? AF_INET: AF_INET6), UNSPECIFIED_COMPARTMENT_ID,
if_idx, buffers, windivert_reinject_complete, (HANDLE)NULL);
}
else if (direction == WINDIVERT_DIRECTION_OUTBOUND)
{
status = FwpsInjectNetworkSendAsync0(handle,
(HANDLE)priority, 0, UNSPECIFIED_COMPARTMENT_ID, buffers,
windivert_reinject_complete, (HANDLE)NULL);
}
else
{
status = FwpsInjectNetworkReceiveAsync0(handle,
(HANDLE)priority, 0, UNSPECIFIED_COMPARTMENT_ID, if_idx,
sub_if_idx, buffers, windivert_reinject_complete, (HANDLE)NULL);
}
windivert_reinject_packet_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 (re)inject complete.
*/
static void NTAPI windivert_reinject_complete(VOID *context,
NET_BUFFER_LIST *buffers, BOOLEAN dispatch_level)
{
PMDL mdl;
PVOID data;
PNET_BUFFER buffer = NET_BUFFER_LIST_FIRST_NB(buffers);
mdl = NET_BUFFER_FIRST_MDL(buffer);
data = MmGetSystemAddressForMdlSafe(mdl, NormalPagePriority);
if (data != NULL)
{
ExFreePoolWithTag(data, WINDIVERT_TAG);
}
IoFreeMdl(mdl);
FwpsFreeNetBufferList0(buffers);
}
/*
* Free a packet.
*/
@@ -2311,10 +2453,6 @@ static void windivert_free_packet(packet_t packet)
{
FwpsFreeCloneNetBufferList0(packet->net_buffer_list, 0);
}
if (packet->data != NULL)
{
ExFreePoolWithTag(packet->data, WINDIVERT_TAG);
}
ExFreePoolWithTag(packet, WINDIVERT_TAG);
}