C++ Stream_SetPosition函数代码示例

static BOOL TestStream_Extent(UINT32 maxSize)
{
	UINT32 i;
	wStream *s = NULL;
	BOOL result = FALSE;

	if (!(s = Stream_New(NULL, 1)))
	{
		printf("%s: Stream_New failed\n", __FUNCTION__);
		return FALSE;
	}

	for (i = 1; i < maxSize; i++)
	{
		if (i % 2)
		{
			if (!Stream_EnsureRemainingCapacity(s, i))
				goto fail;
		}
		else
		{
			if (!Stream_EnsureCapacity(s, i))
				goto fail;
		}

		Stream_SetPosition(s, i);
		Stream_SealLength(s);

		if (!TestStream_Verify(s, i, i, i))
		{
			printf("%s: failed to verify stream in iteration %d\n", __FUNCTION__, i);
			goto fail;
		}
	}

	result = TRUE;

fail:
	if (s)
	{
		Stream_Free(s, TRUE);
	}

	return result;
}

static void rail_virtual_channel_event_data_received(railPlugin* rail,
		void* pData, UINT32 dataLength, UINT32 totalLength, UINT32 dataFlags)
{
	wStream* data_in;

	if ((dataFlags & CHANNEL_FLAG_SUSPEND) || (dataFlags & CHANNEL_FLAG_RESUME))
	{
		return;
	}

	if (dataFlags & CHANNEL_FLAG_FIRST)
	{
		if (rail->data_in)
			Stream_Free(rail->data_in, TRUE);

		rail->data_in = Stream_New(NULL, totalLength);
		if (!rail->data_in)
		{
			WLog_ERR(TAG, "%s: unable to allocate data_in", __FUNCTION__);
			return;
		}
	}

	data_in = rail->data_in;
	if (!Stream_EnsureRemainingCapacity(data_in, (int) dataLength))
	{
		WLog_ERR(TAG, "%s: unable to grow data_in to %d", __FUNCTION__, dataLength);
		return;
	}
	Stream_Write(data_in, pData, dataLength);

	if (dataFlags & CHANNEL_FLAG_LAST)
	{
		if (Stream_Capacity(data_in) != Stream_GetPosition(data_in))
		{
			WLog_ERR(TAG,  "rail_plugin_process_received: read error");
		}

		rail->data_in = NULL;
		Stream_SealLength(data_in);
		Stream_SetPosition(data_in, 0);

		MessageQueue_Post(rail->queue, NULL, 0, (void*) data_in, NULL);
	}
}

static UINT video_control_send_client_notification(VideoClientContext *context, TSMM_CLIENT_NOTIFICATION *notif)
{
	BYTE buf[100];
	wStream *s;
	VIDEO_PLUGIN* video = (VIDEO_PLUGIN *)context->handle;
	IWTSVirtualChannel* channel;
	UINT ret;
	UINT32 cbSize;

	s = Stream_New(buf, 30);
	if (!s)
		return CHANNEL_RC_NO_MEMORY;

	cbSize = 16;
	Stream_Seek_UINT32(s); /* cbSize */
	Stream_Write_UINT32(s, TSMM_PACKET_TYPE_CLIENT_NOTIFICATION); /* PacketType */
	Stream_Write_UINT8(s, notif->PresentationId);
	Stream_Write_UINT8(s, notif->NotificationType);
	Stream_Zero(s, 2);
	if (notif->NotificationType == TSMM_CLIENT_NOTIFICATION_TYPE_FRAMERATE_OVERRIDE)
	{
		Stream_Write_UINT32(s, 16); /* cbData */

		/* TSMM_CLIENT_NOTIFICATION_FRAMERATE_OVERRIDE */
		Stream_Write_UINT32(s, notif->FramerateOverride.Flags);
		Stream_Write_UINT32(s, notif->FramerateOverride.DesiredFrameRate);
		Stream_Zero(s, 4 * 2);

		cbSize += 4 * 4;
	}
	else
	{
		Stream_Write_UINT32(s, 0); /* cbData */
	}

	Stream_SealLength(s);
	Stream_SetPosition(s, 0);
	Stream_Write_UINT32(s, cbSize);
	Stream_Free(s, FALSE);

	channel = video->control_callback->channel_callback->channel;
	ret = channel->Write(channel, cbSize, buf, NULL);

	return ret;
}

int nla_client_authenticate(rdpNla* nla)
{
	wStream* s;
	int status;

	s = Stream_New(NULL, 4096);

	if (!s)
	{
		WLog_ERR(TAG, "Stream_New failed!");
		return -1;
	}

	if (nla_client_begin(nla) < 1)
	{
		Stream_Free(s, TRUE);
		return -1;
	}

	while (nla->state < NLA_STATE_AUTH_INFO)
	{
		Stream_SetPosition(s, 0);

		status = transport_read_pdu(nla->transport, s);

		if (status < 0)
		{
			WLog_ERR(TAG, "nla_client_authenticate failure");
			Stream_Free(s, TRUE);
			return -1;
		}

		status = nla_recv_pdu(nla, s);

		if (status < 0)
		{
			Stream_Free(s, TRUE);
			return -1;
		}
	}

	Stream_Free(s, TRUE);

	return 1;
}

static void wts_read_drdynvc_data_first(rdpPeerChannel* channel, wStream* s, int cbLen, UINT32 length)
{
	int value;

	value = wts_read_variable_uint(s, cbLen, &channel->dvc_total_length);

	if (value == 0)
		return;

	length -= value;

	if (length > channel->dvc_total_length)
		return;

	Stream_SetPosition(channel->receiveData, 0);
	Stream_EnsureRemainingCapacity(channel->receiveData, (int) channel->dvc_total_length);
	Stream_Write(channel->receiveData, Stream_Pointer(s), length);
}

/**
 * Function description
 *
 * @return 0 on success, otherwise a Win32 error code
 */
static UINT dvcman_receive_channel_data(IWTSVirtualChannelManager* pChannelMgr,
					UINT32 ChannelId, wStream* data)
{
	UINT status = CHANNEL_RC_OK;
	DVCMAN_CHANNEL* channel;
	size_t dataSize = Stream_GetRemainingLength(data);

	channel = (DVCMAN_CHANNEL*) dvcman_find_channel_by_id(pChannelMgr, ChannelId);

	if (!channel)
	{
		WLog_ERR(TAG, "ChannelId %d not found!", ChannelId);
		return ERROR_INTERNAL_ERROR;
	}

	if (channel->dvc_data)
	{
		/* Fragmented data */
		if (Stream_GetPosition(channel->dvc_data) + dataSize > (UINT32) Stream_Capacity(channel->dvc_data))
		{
			WLog_ERR(TAG, "data exceeding declared length!");
			Stream_Release(channel->dvc_data);
			channel->dvc_data = NULL;
			return ERROR_INVALID_DATA;
		}

		Stream_Write(channel->dvc_data, Stream_Pointer(data), dataSize);

		if (((size_t) Stream_GetPosition(channel->dvc_data)) >= channel->dvc_data_length)
		{
			Stream_SealLength(channel->dvc_data);
			Stream_SetPosition(channel->dvc_data, 0);
			status = channel->channel_callback->OnDataReceived(channel->channel_callback, channel->dvc_data);
			Stream_Release(channel->dvc_data);
			channel->dvc_data = NULL;
		}
	}
	else
	{
		status = channel->channel_callback->OnDataReceived(channel->channel_callback, data);
	}

	return status;
}

/**
 * Function description
 *
 * @return 0 on success, otherwise a Win32 error code
 */
static UINT encomsp_recv_change_participant_control_level_pdu(
    EncomspServerContext* context, wStream* s, ENCOMSP_ORDER_HEADER* header)
{
	int beg, end;
	ENCOMSP_CHANGE_PARTICIPANT_CONTROL_LEVEL_PDU pdu;
	UINT error = CHANNEL_RC_OK;
	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));

	if (Stream_GetRemainingLength(s) < 6)
	{
		WLog_ERR(TAG, "Not enough data!");
		return ERROR_INVALID_DATA;
	}

	Stream_Read_UINT16(s, pdu.Flags); /* Flags (2 bytes) */
	Stream_Read_UINT32(s, pdu.ParticipantId); /* ParticipantId (4 bytes) */
	end = (int) Stream_GetPosition(s);

	if ((beg + header->Length) < end)
	{
		WLog_ERR(TAG, "Not enough data!");
		return ERROR_INVALID_DATA;
	}

	if ((beg + header->Length) > end)
	{
		if (Stream_GetRemainingLength(s) < ((beg + header->Length) - end))
		{
			WLog_ERR(TAG, "Not enough data!");
			return ERROR_INVALID_DATA;
		}

		Stream_SetPosition(s, (beg + header->Length));
	}

	IFCALLRET(context->ChangeParticipantControlLevel, error, context, &pdu);

	if (error)
		WLog_ERR(TAG, "context->ChangeParticipantControlLevel failed with error %u",
		         error);

	return error;
}

static int update_recv_surfcmd_surface_bits(rdpUpdate* update, wStream* s, UINT32* length)
{
	int pos;
	SURFACE_BITS_COMMAND* cmd = &update->surface_bits_command;

	if (Stream_GetRemainingLength(s) < 20)
		return -1;

	Stream_Read_UINT16(s, cmd->destLeft);
	Stream_Read_UINT16(s, cmd->destTop);
	Stream_Read_UINT16(s, cmd->destRight);
	Stream_Read_UINT16(s, cmd->destBottom);
	Stream_Read_UINT8(s, cmd->bpp);
	if ((cmd->bpp < 1) || (cmd->bpp > 32))
	{
		WLog_ERR(TAG, "invalid bpp value %d", cmd->bpp);
		return FALSE;
	}

	Stream_Seek(s, 2); /* reserved1, reserved2 */
	Stream_Read_UINT8(s, cmd->codecID);
	Stream_Read_UINT16(s, cmd->width);
	Stream_Read_UINT16(s, cmd->height);
	Stream_Read_UINT32(s, cmd->bitmapDataLength);

	if (Stream_GetRemainingLength(s) < cmd->bitmapDataLength)
		return -1;

	pos = Stream_GetPosition(s) + cmd->bitmapDataLength;
	cmd->bitmapData = Stream_Pointer(s);

	Stream_SetPosition(s, pos);
	*length = 20 + cmd->bitmapDataLength;

	WLog_Print(update->log, WLOG_DEBUG,
			   "SurfaceBits: destLeft: %d destTop: %d destRight: %d destBottom: %d "
			   "bpp: %d codecId: %d width: %d height: %d bitmapDataLength: %d",
			   cmd->destLeft, cmd->destTop, cmd->destRight, cmd->destBottom,
			   cmd->bpp, cmd->codecID, cmd->width, cmd->height, cmd->bitmapDataLength);
	IFCALL(update->SurfaceBits, update->context, cmd);

	return 0;
}

void wf_update_encode(wfInfo* wfi)
{

	RFX_RECT rect;
	long height, width;
	BYTE* pDataBits = NULL;
	int stride;

	SURFACE_BITS_COMMAND* cmd;

	wf_info_find_invalid_region(wfi);

	cmd = &wfi->cmd;

	Stream_SetPosition(wfi->s, 0);

	wf_info_getScreenData(wfi, &width, &height, &pDataBits, &stride);

	rect.x = 0;
	rect.y = 0;
	rect.width = (UINT16) width;
	rect.height = (UINT16) height;

	//printf("x:%d y:%d w:%d h:%d\n", wfi->invalid.left, wfi->invalid.top, width, height);

	Stream_Clear(wfi->s);
	rfx_compose_message(wfi->rfx_context, wfi->s, &rect, 1,
		pDataBits, width, height, stride);

	wfi->frame_idx = wfi->rfx_context->frameIdx;

	cmd->destLeft = wfi->invalid.left;
	cmd->destTop = wfi->invalid.top;
	cmd->destRight = wfi->invalid.left + width;
	cmd->destBottom = wfi->invalid.top + height;

	cmd->bpp = 32;
	cmd->codecID = 3;
	cmd->width = width;
	cmd->height = height;
	cmd->bitmapDataLength = Stream_GetPosition(wfi->s);
	cmd->bitmapData = Stream_Buffer(wfi->s);
}

/**
 * Function description
 *
 * @return 0 on success, otherwise a Win32 error code
 */
static UINT rdpgfx_send_reset_graphics_pdu(RdpgfxServerContext* context,
        RDPGFX_RESET_GRAPHICS_PDU* pdu)
{
	UINT32 index;
	MONITOR_DEF* monitor;
	wStream* s;

	/* Check monitorCount. This ensures total size within 340 bytes) */
	if (pdu->monitorCount >= 16)
	{
		WLog_ERR(TAG, "Monitor count MUST be less than or equal to 16: %lu",
		         (unsigned long) pdu->monitorCount);
		return ERROR_INVALID_DATA;
	}

	s = rdpgfx_server_single_packet_new(
	        RDPGFX_CMDID_RESETGRAPHICS,
	        RDPGFX_RESET_GRAPHICS_PDU_SIZE - RDPGFX_HEADER_SIZE);

	if (!s)
	{
		WLog_ERR(TAG, "rdpgfx_server_single_packet_new failed!");
		return CHANNEL_RC_NO_MEMORY;
	}

	Stream_Write_UINT32(s, pdu->width); /* width (4 bytes) */
	Stream_Write_UINT32(s, pdu->height); /* height (4 bytes) */
	Stream_Write_UINT32(s, pdu->monitorCount); /* monitorCount (4 bytes) */

	for (index = 0; index < pdu->monitorCount; index++)
	{
		monitor = &(pdu->monitorDefArray[index]);
		Stream_Write_UINT32(s, monitor->left); /* left (4 bytes) */
		Stream_Write_UINT32(s, monitor->top); /* top (4 bytes) */
		Stream_Write_UINT32(s, monitor->right); /* right (4 bytes) */
		Stream_Write_UINT32(s, monitor->bottom); /* bottom (4 bytes) */
		Stream_Write_UINT32(s, monitor->flags); /* flags (4 bytes) */
	}

	/* pad (total size must be 340 bytes) */
	Stream_SetPosition(s, RDPGFX_RESET_GRAPHICS_PDU_SIZE);
	return rdpgfx_server_single_packet_send(context, s);
}

int dvcman_receive_channel_data(IWTSVirtualChannelManager* pChannelMgr, UINT32 ChannelId, wStream* data)
{
	int status = 0;
	DVCMAN_CHANNEL* channel;
	UINT32 dataSize = Stream_GetRemainingLength(data);

	channel = (DVCMAN_CHANNEL*) dvcman_find_channel_by_id(pChannelMgr, ChannelId);

	if (!channel)
	{
		DEBUG_WARN("ChannelId %d not found!", ChannelId);
		return 1;
	}

	if (channel->dvc_data)
	{
		/* Fragmented data */
		if (Stream_GetPosition(channel->dvc_data) + dataSize > (UINT32) Stream_Capacity(channel->dvc_data))
		{
			DEBUG_WARN("data exceeding declared length!");
			Stream_Release(channel->dvc_data);
			channel->dvc_data = NULL;
			return 1;
		}

		Stream_Write(channel->dvc_data, Stream_Pointer(data), dataSize);

		if (((size_t) Stream_GetPosition(channel->dvc_data)) >= Stream_Capacity(channel->dvc_data))
		{
			Stream_SealLength(channel->dvc_data);
			Stream_SetPosition(channel->dvc_data, 0);
			status = channel->channel_callback->OnDataReceived(channel->channel_callback, channel->dvc_data);
			Stream_Release(channel->dvc_data);
			channel->dvc_data = NULL;
		}
	}
	else
	{
		status = channel->channel_callback->OnDataReceived(channel->channel_callback, data);
	}

	return status;
}

static void svc_plugin_process_received(rdpSvcPlugin* plugin, void* pData, UINT32 dataLength,
	UINT32 totalLength, UINT32 dataFlags)
{
	wStream* s;
	
	if ((dataFlags & CHANNEL_FLAG_SUSPEND) || (dataFlags & CHANNEL_FLAG_RESUME))
	{
		/*
		 * According to MS-RDPBCGR 2.2.6.1, "All virtual channel traffic MUST be suspended.
		 * This flag is only valid in server-to-client virtual channel traffic. It MUST be
		 * ignored in client-to-server data." Thus it would be best practice to cease data
		 * transmission. However, simply returning here avoids a crash.
		 */
		return;
	}

	if (dataFlags & CHANNEL_FLAG_FIRST)
	{
		if (plugin->data_in != NULL)
			Stream_Free(plugin->data_in, TRUE);

		plugin->data_in = Stream_New(NULL, totalLength);
	}

	s = plugin->data_in;
	Stream_EnsureRemainingCapacity(s, (int) dataLength);
	Stream_Write(s, pData, dataLength);

	if (dataFlags & CHANNEL_FLAG_LAST)
	{
		if (Stream_Capacity(s) != Stream_GetPosition(s))
		{
			fprintf(stderr, "svc_plugin_process_received: read error\n");
		}

		plugin->data_in = NULL;
		Stream_SealLength(s);
		Stream_SetPosition(s, 0);

		MessageQueue_Post(plugin->MsgPipe->In, NULL, 0, (void*) s, NULL);
	}
}

int freerds_client_outbound_vblank_event(rdsModuleConnector* connector)
{
	int length;
	int status;
	wStream* s;
	RDS_MSG_VBLANK_EVENT msg;

	msg.msgFlags = 0;
	msg.type = RDS_CLIENT_VBLANK_EVENT;

	s = connector->OutboundStream;
	Stream_SetPosition(s, 0);

	length = freerds_write_vblank_event(NULL, &msg);
	freerds_write_vblank_event(s, &msg);

	status = freerds_named_pipe_write(connector->hClientPipe, Stream_Buffer(s), length);

	return status;
}

/**
 * Function description
 *
 * @return 0 on success, otherwise a Win32 error code
 */
static UINT encomsp_recv_graphics_stream_resumed_pdu(encomspPlugin* encomsp, wStream* s, ENCOMSP_ORDER_HEADER* header)
{
	int beg, end;
	EncomspClientContext* context;
	ENCOMSP_GRAPHICS_STREAM_RESUMED_PDU pdu;
	UINT error = CHANNEL_RC_OK;

	context = encomsp_get_client_interface(encomsp);

	if (!context)
		return ERROR_INVALID_HANDLE;

	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;

	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));

	end = (int) Stream_GetPosition(s);

	if ((beg + header->Length) < end)
	{
		WLog_ERR(TAG, "Not enought data!");
		return ERROR_INVALID_DATA;
	}

	if ((beg + header->Length) > end)
	{
		if (Stream_GetRemainingLength(s) < (size_t) ((beg + header->Length) - end))
		{
			WLog_ERR(TAG, "Not enought data!");
			return ERROR_INVALID_DATA;
		}

		Stream_SetPosition(s, (beg + header->Length));
	}

	IFCALLRET(context->GraphicsStreamResumed, error, context, &pdu);
	if (error)
		WLog_ERR(TAG, "context->GraphicsStreamResumed failed with error %lu", error);

	return error;
}

RPC_PDU* rpc_client_receive_pool_take(rdpRpc* rpc)
{
	RPC_PDU* pdu = NULL;

	if (WaitForSingleObject(Queue_Event(rpc->client->ReceivePool), 0) == WAIT_OBJECT_0)
		pdu = Queue_Dequeue(rpc->client->ReceivePool);

	if (!pdu)
	{
		pdu = (RPC_PDU*) malloc(sizeof(RPC_PDU));
		pdu->s = Stream_New(NULL, rpc->max_recv_frag);
	}

	pdu->CallId = 0;
	pdu->Flags = 0;

	Stream_Length(pdu->s) = 0;
	Stream_SetPosition(pdu->s, 0);

	return pdu;
}