一、前言

1.1 发包的BlinkToRadio的数据包格式

如下，注意：AM层类型(1byte)即handlerID使可以在组件中修改的。

二、混淆基站源码分析

2.1 Makefile

COMPONENT=BaseStationC
CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS
CFLAGS += -DCC2420_NO_ADDRESS_RECOGNITION
CFLAGS += -DTASKLET_IS_TASK
CFLAGS += -DCC2420_DEF_CHANNEL=14
include $(MAKERULES)

这里加多了几句，就可以监听同样信道中的消息

• CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS
  这个表示不返回ACK
• CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS
  表示不开启地址识别

CFLAGS += -DCC2420_NO_ACKNOWLEDGEMENTS
CFLAGS += -DCC2420_NO_ADDRESS_RECOGNITION
CFLAGS += -DTASKLET_IS_TASK

2.2 组件连接

configuration BaseStationC {
}
implementation {
  components MainC, BaseStationP, LedsC;
  components SerialActiveMessageC as Serial;
  
  MainC.Boot <- BaseStationP;

  BaseStationP.RadioControl -> Radio;
  BaseStationP.SerialControl -> Serial;
  
  BaseStationP.UartSend -> Serial;
  BaseStationP.UartReceive -> Serial.Receive;
  BaseStationP.UartPacket -> Serial;
  BaseStationP.UartAMPacket -> Serial;
  
  //radio
  components ActiveMessageC as Radio
  BaseStationP.RadioSend -> Radio;
  BaseStationP.RadioReceive -> Radio.Receive;
  BaseStationP.RadioSnoop -> Radio.Snoop;
  BaseStationP.RadioPacket -> Radio;
  BaseStationP.RadioAMPacket -> Radio;
  
  BaseStationP.Leds -> LedsC;
}

• BaseStationP.RadioSnoop -> Radio.Snoop;
  通过这个接口去拿监听的包

2.3 主逻辑代码

#include "AM.h"
#include "Serial.h"

module BaseStationP @safe() {
  uses {
    interface Boot;
    interface SplitControl as SerialControl;
    interface SplitControl as RadioControl;

    interface AMSend as UartSend[am_id_t id];
    interface Receive as UartReceive[am_id_t id];
    interface Packet as UartPacket;
    interface AMPacket as UartAMPacket;
    
    interface AMSend as RadioSend[am_id_t id];
    interface Receive as RadioReceive[am_id_t id];
    interface Receive as RadioSnoop[am_id_t id];
    interface Packet as RadioPacket;
    interface AMPacket as RadioAMPacket;

    interface Leds;
  }
}

implementation
{
  enum {
    UART_QUEUE_LEN = 12,
    RADIO_QUEUE_LEN = 12,
  };

  message_t  uartQueueBufs[UART_QUEUE_LEN];
  message_t  * ONE_NOK uartQueue[UART_QUEUE_LEN];
  uint8_t    uartIn, uartOut;
  bool       uartBusy, uartFull;

  message_t  radioQueueBufs[RADIO_QUEUE_LEN];
  message_t  * ONE_NOK radioQueue[RADIO_QUEUE_LEN];
  uint8_t    radioIn, radioOut;
  bool       radioBusy, radioFull;

  task void uartSendTask();
  task void radioSendTask();

  void dropBlink() {
    call Leds.led2Toggle();
  }

  void failBlink() {
    call Leds.led2Toggle();
  }

  event void Boot.booted() {
    uint8_t i;

    for (i = 0; i < UART_QUEUE_LEN; i++)
      uartQueue[i] = &uartQueueBufs[i];
    uartIn = uartOut = 0;
    uartBusy = FALSE;
    uartFull = TRUE;

    for (i = 0; i < RADIO_QUEUE_LEN; i++)
      radioQueue[i] = &radioQueueBufs[i];
    radioIn = radioOut = 0;
    radioBusy = FALSE;
    radioFull = FALSE;

    call RadioControl.start();
    call SerialControl.start();
  }

  event void RadioControl.startDone(error_t error) {
    if (error == SUCCESS) {
      radioFull = FALSE;
    }
  }

  event void SerialControl.startDone(error_t error) {
    if (error == SUCCESS) {
      uartFull = FALSE;
    }
  }

  event void SerialControl.stopDone(error_t error) {}
  event void RadioControl.stopDone(error_t error) {}

  uint8_t count = 0;

  message_t* ONE receive(message_t* ONE msg, void* payload, uint8_t len);
  
  event message_t *RadioSnoop.receive[am_id_t id](message_t *msg,
						    void *payload,
						    uint8_t len) {
    return receive(msg, payload, len);
  }
  
  event message_t *RadioReceive.receive[am_id_t id](message_t *msg,
						    void *payload,
						    uint8_t len) {
    return receive(msg, payload, len);
  }

  message_t* receive(message_t *msg, void *payload, uint8_t len) {
    message_t *ret = msg;

    atomic {
      if (!uartFull)
	{
	  ret = uartQueue[uartIn];
	  uartQueue[uartIn] = msg;

	  uartIn = (uartIn + 1) % UART_QUEUE_LEN;
	
	  if (uartIn == uartOut)
	    uartFull = TRUE;

	  if (!uartBusy)
	    {
	      post uartSendTask();
	      uartBusy = TRUE;
	    }
	}
      else
	dropBlink();
    }
    
    return ret;
  }

  uint8_t tmpLen;
  
  task void uartSendTask() {
    uint8_t len;
    am_id_t id;
    am_addr_t addr, src;
    message_t* msg;
    atomic
      if (uartIn == uartOut && !uartFull)
	{
	  uartBusy = FALSE;
	  return;
	}

    msg = uartQueue[uartOut];
    tmpLen = len = call RadioPacket.payloadLength(msg);
    id = call RadioAMPacket.type(msg);
    addr = call RadioAMPacket.destination(msg);
    src = call RadioAMPacket.source(msg);
    call UartPacket.clear(msg);
    call UartAMPacket.setSource(msg, src);

    if (call UartSend.send[id](addr, uartQueue[uartOut], len) == SUCCESS)
      call Leds.led1Toggle();
    else
      {
	failBlink();
	post uartSendTask();
      }
  }

  event void UartSend.sendDone[am_id_t id](message_t* msg, error_t error) {
    if (error != SUCCESS)
      failBlink();
    else
      atomic
	if (msg == uartQueue[uartOut])
	  {
	    if (++uartOut >= UART_QUEUE_LEN)
	      uartOut = 0;
	    if (uartFull)
	      uartFull = FALSE;
	  }
    post uartSendTask();
  }

  event message_t *UartReceive.receive[am_id_t id](message_t *msg,
						   void *payload,
						   uint8_t len) {
    message_t *ret = msg;
    bool reflectToken = FALSE;

    atomic
      if (!radioFull)
	{
	  reflectToken = TRUE;
	  ret = radioQueue[radioIn];
	  radioQueue[radioIn] = msg;
	  if (++radioIn >= RADIO_QUEUE_LEN)
	    radioIn = 0;
	  if (radioIn == radioOut)
	    radioFull = TRUE;

	  if (!radioBusy)
	    {
	      post radioSendTask();
	      radioBusy = TRUE;
	    }
	}
      else
	dropBlink();

    if (reflectToken) {
      //call UartTokenReceive.ReflectToken(Token);
    }
    
    return ret;
  }

  task void radioSendTask() {
    uint8_t len;
    am_id_t id;
    am_addr_t addr,source;
    message_t* msg;
    
    atomic
      if (radioIn == radioOut && !radioFull)
	{
	  radioBusy = FALSE;
	  return;
	}

    msg = radioQueue[radioOut];
    len = call UartPacket.payloadLength(msg);
    addr = call UartAMPacket.destination(msg);
    source = call UartAMPacket.source(msg);
    id = call UartAMPacket.type(msg);

    call RadioPacket.clear(msg);
    call RadioAMPacket.setSource(msg, source);
    
    if (call RadioSend.send[id](addr, msg, len) == SUCCESS)
      call Leds.led0Toggle();
    else
      {
	failBlink();
	post radioSendTask();
      }
  }

  event void RadioSend.sendDone[am_id_t id](message_t* msg, error_t error) {
    if (error != SUCCESS)
      failBlink();
    else
      atomic
	if (msg == radioQueue[radioOut])
	  {
	    if (++radioOut >= RADIO_QUEUE_LEN)
	      radioOut = 0;
	    if (radioFull)
	      radioFull = FALSE;
	  }
    
    post radioSendTask();
  }
}  

步骤如下：

1. 上电开机后
   1.1 初始化队列
   1.2 开启无线控制器call RadioControl.start();
   1.3 开启串口控制器call SerialControl.start();
2. 编写接收窃听到的包的回调函数
   2.1 通过串口把数据输出

event message_t *RadioSnoop.receive[am_id_t id](message_t *msg, void *payload,uint8_t len) 
{
    return receive(msg, payload, len);
}