nes-proj/platform/avr-ravenusb/sicslow_ethernet.c

/**
 * \file sicslow_ethernet.c
 *         Routines to interface between Ethernet and 6LowPan
 *
 * \author
 *         Colin O'Flynn <coflynn@newae.com>
 *
 * \addtogroup usbstick 
 */

/* Copyright (c) 2008 by:
 * Colin O'Flynn coflynn@newae.com
 * Eric Gnoske egnoske@gmail.com
 * Blake Leverett bleverett@gmail.com
 * Mike Vidales mavida404@gmail.com
 * Kevin Brown kbrown3@uccs.edu
 * Nate Bohlmann nate@elfwerks.com
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 * * Neither the name of the copyright holders nor the names of
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/**
   \ingroup usbstick
   \defgroup sicslowinterop 6LowPan Ethernet Interop
   @{
*/


/**
   \par Ethernet to 6LowPan Address Translation
   
   It should be obvious that since 802.15.4 addresses are 8 
   bytes, and 802.3 addresses are 6 bytes, some form of 
   address translation is needed. These routines provide this

   \par 802.3 Address Formats

   802.3 MAC addresses used here have this form:
   
   \verbatim
   +----+----+----+----+----+----+----+----+
   +    +    +    +    +    + TR + GL + MU +
   +----+----+----+----+----+----+----+----+
   \endverbatim


   It can be seen this is like a normal ethernet MAC address, 
   with GL being the Global/Local bit, and MU being the
   Multicast/Unicast bit.

   The addition is the 'TR' bit, which if set indicates that
   the address must be translated when going between 802.15.4
   and 802.3. 

   \par Address Translation

   If the TRANSLATE (TR) bit is CLEAR, this means the 5th and
   4th LSBytes of the 802.15.4 address are fffe, aka the address
   has the hexidecial form:
   
   xxxxxxfffexxxxxx

   \note
   You should always aim to set the 802.15.4 addresses
   of the devices on your network to ones that will
   satisfy this requirement. Some examples are:
   \note
   0x02 23 42 ff fe 73 92 28
   \note
   0x82 00 82 ff fe cd ee 22

   \note
   So the most significant octets MUST 
   have bit 0 CLEAR, bit 1 SET, and bit 2 CLEAR. The remaining
   bits in this octet can be anything.

   If the TRANSLATE bit is SET, this means the address on the 
   802.3 side does not directly convert to an 802.15.4 address.
   To translate it, the remainder of the octet is used as an
   index in a look-up table. This look-up table simply stores
   the 4th, 5th, and 8th octet of the 802.15.4 address, and attaches
   them to the remaining 5 bytes of the 802.3 address.

   In this way there can be 32 different 802.15.4 'prefixes', 
   requiring only 96 bytes of RAM in a storage table on the
   802.3 to 802.15.4 bridge. 
  
   Mulitcast addresses on 802.3 are mapped to broadcast addresses on
   802.15.4 and vis-versa. Since IPv6 does not use 802.3 broadcast, 
   this code will drop all 802.3 broadcast packets. They are most
   likely something unwanted, such as IPv4 packets that snuck in.

   \par Notes on how addresses are stored

   An 802.15.4 address will be reported for example as:

   0x8877665544332211

   Stored in the array as passed to these functions, it will be:
   \verbatim
   array[0] = 0x88;
   array[1] = 0x77;
   array[2] = 0x66;
   etc.
   \endverbatim

   An 802.3 address will be reported for example as:
   02:43:53:35:45:45

   Stored in the array as passed to these functions, it will be:
   \verbatim
   array[0] = 0x02;
   array[1] = 0x43;
   array[2] = 0x53;
   array[3] = 0x35
   etc.
   \endverbatim
*/

#include "uip.h"
#include "uip_arp.h" //For ethernet header structure
#include "zmac.h"
#include "frame.h"
#include "net/rime.h"
#include "sicslowpan.h"
#include "sicslow_ethernet.h"
#include "rndis/rndis_protocol.h"
#include "rndis/rndis_task.h"
#include "radio.h"

#include <stdint.h>
#include <stdio.h>
#include <string.h>

//#define PRINTF printf
#define PRINTF(...)

#define UIP_IP_BUF   ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
#define ETHBUF(x) ((struct uip_eth_hdr *)x)

//For little endian, such as our friend mr. AVR
#ifndef LSB
#define LSB(u16)     (((uint8_t  *)&(u16))[0])  //!< Least significant byte of \a u16.
#define MSB(u16)     (((uint8_t  *)&(u16))[1])  //!< Most significant byte of \a u16.
#endif

extern uint64_t rndis_ethernet_addr;
extern void (*pinput)(const struct mac_driver *r);
void (*sicslowinput)(const struct mac_driver *r);
parsed_frame_t * parsed_frame;
usbstick_mode_t usbstick_mode;

uint8_t mac_createSicslowpanLongAddr(uint8_t * ethernet, uip_lladdr_t * lowpan);
uint8_t mac_createEthernetAddr(uint8_t * ethernet, uip_lladdr_t * lowpan);
uint8_t memcmp_reverse(uint8_t * a, uint8_t * b, uint8_t num);
void mac_ethhijack_nondata(const struct mac_driver *r);
void mac_ethhijack(const struct mac_driver *r);

extern void (*sicslowmac_snifferhook)(const struct mac_driver *r);


//! Location of TRANSLATE (TR) bit in Ethernet address
#define TRANSLATE_BIT_MASK (1<<2) 
//! Location of LOCAL (GL) bit in Ethernet address
#define LOCAL_BIT_MASK     (1<<1)
//! Location of MULTICAST (MU) bit in Ethernet address
#define MULTICAST_BIT_MASK (1<<0)

#define PREFIX_BUFFER_SIZE 32

uint8_t prefixCounter;
uint8_t prefixBuffer[PREFIX_BUFFER_SIZE][3];

/* 6lowpan max size + ethernet header size + 1 */
uint8_t raw_buf[127+ UIP_LLH_LEN +1];


void tcpip_input( void )
{
  mac_LowpanToEthernet();
}

/**
 * \brief   Perform any setup needed
 */
 struct mac_driver * pmac;
void mac_ethernetSetup(void)
{
  usbstick_mode.sicslowpan = 1;
  usbstick_mode.sendToRf = 1;
  usbstick_mode.translate = 1;
  usbstick_mode.raw = 1;
  
  sicslowinput = pinput;
  
  
  pmac = sicslowmac_get_driver();			
  pmac->set_receive_function(mac_ethhijack);			  
  sicslowmac_snifferhook = mac_ethhijack_nondata;
}


/**
 * \brief   Take a packet received over the ethernet link, and send it
 * out over 802.15.4
 */
void mac_ethernetToLowpan(uint8_t * ethHeader)
{
  //Dest address
  uip_lladdr_t destAddr;
  uip_lladdr_t *destAddrPtr = NULL;

  PRINTF("Packet type: %x\n", ((struct uip_eth_hdr *) ethHeader)->type);

  //If not IPv6 we don't do anything
  if (((struct uip_eth_hdr *) ethHeader)->type != HTONS(UIP_ETHTYPE_IPV6)) {
    printf("eth2low: Packet is not IPv6, dropping\n");
    rndis_stat.txbad++;
    uip_len = 0;
    return;
  }

  // In sniffer mode we don't ever send anything
  if (usbstick_mode.sendToRf == 0) { 
    uip_len = 0;
    return;
  }

  /* IPv6 uses 33-33-xx-xx-xx-xx prefix for multicast ND stuff */
  if ( (((struct uip_eth_hdr *) ethHeader)->dest.addr[0] == 0x33) &&
       (((struct uip_eth_hdr *) ethHeader)->dest.addr[1] == 0x33) )
  {
    PRINTF("eth2low: Ethernet multicast packet received\n");
    ;//Do Nothing		 
  } else if ( (((struct uip_eth_hdr *) ethHeader)->dest.addr[0] == 0xFF) &&
            (((struct uip_eth_hdr *) ethHeader)->dest.addr[1] == 0xFF) && 
            (((struct uip_eth_hdr *) ethHeader)->dest.addr[2] == 0xFF) && 
            (((struct uip_eth_hdr *) ethHeader)->dest.addr[3] == 0xFF) && 
            (((struct uip_eth_hdr *) ethHeader)->dest.addr[4] == 0xFF) && 
            (((struct uip_eth_hdr *) ethHeader)->dest.addr[5] == 0xFF) ) {
    /* IPv6 does not use broadcast addresses, hence this should not happen */
    PRINTF("eth2low: Ethernet broadcast address received, should not happen?\n");
    rndis_stat.txbad++;
    uip_len = 0;
    return;
  } else {
    PRINTF("eth2low: Addressed packet received... ");
    //Check this returns OK
    if (mac_createSicslowpanLongAddr( &(((struct uip_eth_hdr *) ethHeader)->dest.addr[0]), &destAddr) == 0) {
      PRINTF(" translation failed\n");
      rndis_stat.txbad++;
      uip_len = 0;
      return;
    }	
    PRINTF(" translated OK\n");
    destAddrPtr = &destAddr;
  }

  //Remove header from length before passing onward
  uip_len -= UIP_LLH_LEN;

  //Some IP packets have link layer in them, need to change them around!
  if (usbstick_mode.translate) {
    uint8_t transReturn = mac_translateIPLinkLayer(ll_802154_type);
    PRINTF("IPTranslation: returns %d\n", transReturn);
  }
	
  if (usbstick_mode.sendToRf){
	  tcpip_output(destAddrPtr);
	  rndis_stat.txok++;
  }
  
  uip_len = 0;

}


/**
 * \brief Take a packet received over the 802.15.4 link, and send it
 * out over ethernet, performing any translations needed.
 */
void mac_LowpanToEthernet(void)
{
  parsed_frame = sicslowmac_get_frame();

  //Setup generic ethernet stuff
  ETHBUF(uip_buf)->type = htons(UIP_ETHTYPE_IPV6);
  
  //Check for broadcast message
  //if(rimeaddr_cmp((const rimeaddr_t *)destAddr, &rimeaddr_null)) {
  if(  ( parsed_frame->fcf->destAddrMode == SHORTADDRMODE) &&
       ( parsed_frame->dest_addr->addr16 == 0xffff) ) {
    ETHBUF(uip_buf)->dest.addr[0] = 0x33;
    ETHBUF(uip_buf)->dest.addr[1] = 0x33;
    ETHBUF(uip_buf)->dest.addr[2] = UIP_IP_BUF->destipaddr.u8[12];
    ETHBUF(uip_buf)->dest.addr[3] = UIP_IP_BUF->destipaddr.u8[13];
    ETHBUF(uip_buf)->dest.addr[4] = UIP_IP_BUF->destipaddr.u8[14];
    ETHBUF(uip_buf)->dest.addr[5] = UIP_IP_BUF->destipaddr.u8[15];
  } else {
	//Otherwise we have a real address
	mac_createEthernetAddr((uint8_t *) &(ETHBUF(uip_buf)->dest.addr[0]),
                        (uip_lladdr_t *)rimebuf_addr(RIMEBUF_ADDR_RECEIVER));
  }
	

  mac_createEthernetAddr((uint8_t *) &(ETHBUF(uip_buf)->src.addr[0]),
                         (uip_lladdr_t *)rimebuf_addr(RIMEBUF_ADDR_SENDER));

  //We only do address translation in network mode!
  if (usbstick_mode.translate) {
    //Some IP packets have link layer in them, need to change them around!
    mac_translateIPLinkLayer(ll_8023_type);
  }

  PRINTF("Low2Eth: Sending packet to ethernet\n");

  uip_len += UIP_LLH_LEN;

  rndis_send(uip_buf, uip_len);
  rndis_stat.rxok++;
  uip_len = 0;
}

/**
 * \brief Translate IP packet's possible link-layer addresses, passing
 *        the message to the appropriate higher level function for this
 *        packet (aka: ICMP)
 * \param target The target we want to end up with - either ll_8023_type
 *        for ethernet, or ll_802154_type for 802.15.4
 * \return    Returns how successful the translation was
 * \retval 0  Addresses, if present, were translated.
 * \retval <0 Negative return values indicate various errors, as defined
 *            by the higher level function.
 */
int8_t mac_translateIPLinkLayer(lltype_t target)
{
  if (UIP_IP_BUF->proto == UIP_PROTO_ICMP6) {
    PRINTF("eth2low: ICMP Message detected\n");
    return mac_translateIcmpLinkLayer(target);
  }
  return 0;
}

#include "net/uip-icmp6.h"
#include "net/uip-nd6.h"

typedef struct {
  uint8_t type;
  uint8_t length;
  uint8_t data[16];
} icmp_opts_t;

#define UIP_ICMP_BUF     ((struct uip_icmp_hdr *)&uip_buf[UIP_LLH_LEN + UIP_IPH_LEN])
#define UIP_ICMP_OPTS(x) ((icmp_opts_t *)&uip_buf[UIP_LLH_LEN + UIP_IPH_LEN + x])

void slide(uint8_t * data, uint8_t length, int16_t slide);

/**
 * \brief Translate the link-layer (L2) addresses in an ICMP packet.
 *        This will just be NA/NS/RA/RS packets currently.
 * \param target The target we want to end up with - either ll_8023_type
 *        for ethernet, or ll_802154_type for 802.15.4
 * \return       Returns how successful the translation was
 * \retval 0     Addresses, if present, were translated.
 * \retval -1    ICMP message was unknown type, nothing done.
 * \retval -2    ICMP Length does not make sense?
 * \retval -3    Unknown 'target' type
 */
int8_t mac_translateIcmpLinkLayer(lltype_t target)
{
  uint16_t icmp_opt_offset = 0;
  int16_t len = UIP_IP_BUF->len[1] | (UIP_IP_BUF->len[0] << 8);

  uint16_t iplen;

  uint8_t i;

  int16_t sizechange;

  uint8_t llbuf[16];

  //Figure out offset to start of options
  switch(UIP_ICMP_BUF->type) {
    case ICMP6_NS:
    case ICMP6_NA:
      icmp_opt_offset = 24;
      break;

    case ICMP6_RS:
      icmp_opt_offset = 8;
      break;

    case ICMP6_RA:
      icmp_opt_offset = 16;
      break;

    case ICMP6_REDIRECT:
      icmp_opt_offset = 40;
      break;   

      /** Things without link-layer */
    case ICMP6_DST_UNREACH:
    case ICMP6_PACKET_TOO_BIG:
    case ICMP6_TIME_EXCEEDED:	
    case ICMP6_PARAM_PROB:
    case ICMP6_ECHO_REQUEST:  
    case ICMP6_ECHO_REPLY: 
      return 0;
      break;

    default:
      return -1;
  }

  //Figure out length of options
  len -= icmp_opt_offset;

  //Sanity check
  if (len < 8) return -2; 

  //While we have options to do...
  while (len >= 8){
    
    //If we have one of these, we have something useful!
    if (((UIP_ICMP_OPTS(icmp_opt_offset)->type) == UIP_ND6_OPT_SLLAO) || 
        ((UIP_ICMP_OPTS(icmp_opt_offset)->type) == UIP_ND6_OPT_TLLAO) ) {
      
      /* Shrinking the buffer may thrash things, so we store the old
         link-layer address */
      for(i = 0; i < (UIP_ICMP_OPTS(icmp_opt_offset)->length*8 - 2); i++) {
        llbuf[i] = UIP_ICMP_OPTS(icmp_opt_offset)->data[i];
      }

      //Shrink/grow buffer as needed
      if (target == ll_802154_type) {
        //Current is 802.3, Hence current link-layer option is 6 extra bytes
        sizechange = 8;
        slide(UIP_ICMP_OPTS(icmp_opt_offset)->data + 6, len - 6, sizechange);
      } else if (target == ll_8023_type) {
        /* Current is 802.15.4, Hence current link-layer option is 14 extra
         * bytes.
         * (Actual LL is 8 bytes, but total option length is in multiples of
         * 8 Bytes, hence 8 + 2 = 10. Closest is 16 bytes, then 16 bytes for
         * total optional length - 2 bytes for type + length leaves 14 )
         */
        sizechange = -8;
        slide(UIP_ICMP_OPTS(icmp_opt_offset)->data + 14, len - 14, sizechange);
      } else {
        return -3; //Uh-oh!
      }
      
      //Translate addresses
      if (target == ll_802154_type) {
        mac_createSicslowpanLongAddr(llbuf, (uip_lladdr_t *)UIP_ICMP_OPTS(icmp_opt_offset)->data);
      } else {
        mac_createEthernetAddr(UIP_ICMP_OPTS(icmp_opt_offset)->data, (uip_lladdr_t *)llbuf);
      }
      
      //Adjust the length
      if (target == ll_802154_type) {
        UIP_ICMP_OPTS(icmp_opt_offset)->length = 2;
      } else {
        UIP_ICMP_OPTS(icmp_opt_offset)->length = 1;
      }

      //Adjust the IP header length, as well as uIP length
      iplen = UIP_IP_BUF->len[1] | (UIP_IP_BUF->len[0]<<8);
      iplen += sizechange;
      len += sizechange;
      
      UIP_IP_BUF->len[1] = (uint8_t)iplen;
      UIP_IP_BUF->len[0] = (uint8_t)(iplen >> 8);

      uip_len += sizechange;

      //We broke ICMP checksum, be sure to fix that
      UIP_ICMP_BUF->icmpchksum = 0;
      UIP_ICMP_BUF->icmpchksum = ~uip_icmp6chksum(); 

      //Finally set up next run in while loop
      len -= 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
      icmp_opt_offset += 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
    } else {
	  
      //Not an option we care about, ignore it
      len -= 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
	      
      //This shouldn't happen!
      if (UIP_ICMP_OPTS(icmp_opt_offset)->length == 0) {
        PRINTF("Option in ND packet has length zero, error?\n");
        len = 0;
      }

      icmp_opt_offset += 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
      
    } //If ICMP_OPT is one we care about
   
  } //while(len >= 8)

  return 0;

}


/**
 * \brief Create a 802.15.4 long address from a 802.3 address
 * \param ethernet   Pointer to ethernet address
 * \param lowpan     Pointer to 802.15.4 address
 */
uint8_t mac_createSicslowpanLongAddr(uint8_t * ethernet, uip_lladdr_t * lowpan)
{
  uint8_t index;
  uint8_t i;
  
  
  //Special case - if the address is our address, we just copy over what we know to be
  //our 802.15.4 address
  
  if (memcmp_reverse((uint8_t *)&rndis_ethernet_addr, ethernet, 6) == 0) {
		memcpy((uint8_t *)lowpan, &macLongAddr, 8);
		byte_reverse((uint8_t *)lowpan, 8);

		return 1;
	}
	
  //Check if translate bit is set, hence we have to look up the prefix
  if (ethernet[0] & TRANSLATE_BIT_MASK) {

    //Get top bits
    index = ethernet[0] >> 3;

    //Check this is plausible...
    if (index >= prefixCounter) {
      return 0;
    }

    //Copy over prefix
    lowpan->addr[0] = prefixBuffer[index][0];
	lowpan->addr[3] = prefixBuffer[index][1];
	lowpan->addr[4] = prefixBuffer[index][2];
   
    //Bit is clear
    //so we copy all six
  } else {
    lowpan->addr[0] = ethernet[0];
    lowpan->addr[3] = 0xff;
    lowpan->addr[4] = 0xfe;
  }

  //Copy over reamining five bytes
    lowpan->addr[1] = ethernet[1];
    lowpan->addr[2] = ethernet[2];
    lowpan->addr[5] = ethernet[3];
    lowpan->addr[6] = ethernet[4];
    lowpan->addr[7] = ethernet[5];

  return 1;
}


/**
 * \brief Create a 802.3 address from a 802.15.4 long address
 * \param ethernet   Pointer to ethernet address
 * \param lowpan     Pointer to 802.15.4 address
 */
uint8_t mac_createEthernetAddr(uint8_t * ethernet, uip_lladdr_t * lowpan)
{
  uint8_t index = 0;
  uint8_t i,j, match;
  
   //Special case - if the address is our address, we just copy over what we know to be
  //our 802.3 address
  if (memcmp_reverse((uint8_t *)&macLongAddr, (uint8_t *)lowpan, 8) == 0) {
		memcpy(ethernet, &rndis_ethernet_addr, 6);
		byte_reverse(ethernet, 6);

		return 1;
	} 
  

  //Check if we need to do anything:
  if ((lowpan->addr[3] == 0xff) && (lowpan->addr[4] == 0xfe) &&
      ((lowpan->addr[0] & TRANSLATE_BIT_MASK) == 0) &&
      ((lowpan->addr[0] & MULTICAST_BIT_MASK) == 0) &&
      (lowpan->addr[0] & LOCAL_BIT_MASK)) {
		
    /** Nope: just copy over 6 bytes **/
      ethernet[0] = lowpan->addr[0];
	  ethernet[1] = lowpan->addr[1];
	  ethernet[2] = lowpan->addr[2];
	  ethernet[3] = lowpan->addr[5];
	  ethernet[4] = lowpan->addr[6];
	  ethernet[5] = lowpan->addr[7];
	  
	
  } else {

    /** Yes: need to store prefix **/
    for (i = 0; i < prefixCounter; i++)	{	
      //Check the current prefix - if it fails, check next one
    

       if ((lowpan->addr[0] == prefixBuffer[i][0]) && 
           (lowpan->addr[3] == prefixBuffer[i][1]) &&
           (lowpan->addr[4] == prefixBuffer[i][2])) {
			break;
	   }
	
    }
    
    index = i;

    //Deal with overflow, iron-fist style
    if (index >= PREFIX_BUFFER_SIZE) {
      index = 0;
      prefixCounter = PREFIX_BUFFER_SIZE;
    } else {	
      //Are we making a new one?
      if (index == prefixCounter) {
        prefixCounter++;
      }
    }

    //Copy the prefix over, no matter if we have a new or old one
    prefixBuffer[index][0] = lowpan->addr[0];
	prefixBuffer[index][1] = lowpan->addr[3];
	prefixBuffer[index][2] = lowpan->addr[4];
  
    //Create ethernet MAC address now
    ethernet[1] = lowpan->addr[1];
	ethernet[2] = lowpan->addr[2];
	ethernet[3] = lowpan->addr[5];
	ethernet[4] = lowpan->addr[6];
    ethernet[5] = lowpan->addr[7];
	
	
    ethernet[0] = TRANSLATE_BIT_MASK | LOCAL_BIT_MASK | (index << 3);
  }
  return 1;
}


/**
 * \brief        Slide the pointed to memory up a certain amount,
 *               growing/shrinking a buffer
 * \param data   Pointer to start of data buffer
 * \param length Length of the data buffer
 * \param slide  How many bytes to slide the buffer up in memory (if +) or
 *               down in memory (if -)
 */
void slide(uint8_t * data, uint8_t length, int16_t slide)
{
  //Sanity checks
  if (!length) return;
  if (!slide) return;

  uint8_t i = 0;

  while(length) {
    length--;

    //If we are sliding up, we do from the top of the buffer down
    if (slide > 0) {
      *(data + length + slide) = *(data + length);	

      //If we are sliding down, we do from the bottom of the buffer up
    } else {
      *(data + slide + i) = *(data + i);
    }
    
    i++;
  }
}

/*--------------------------------------------------------------------*/
/** \brief Process a received 6lowpan packet. Hijack function.
 *  \param r The MAC layer
 *
 *  The 6lowpan packet is put in rimebuf by the MAC. This routine calls
 *  any other needed layers (either 6lowpan, or just raw ethernet dump)
 */
void mac_ethhijack(const struct mac_driver *r)
{
	if (usbstick_mode.raw)
		mac_802154raw(r);
		
	if (usbstick_mode.sicslowpan)
		sicslowinput(r);	

}

void mac_ethhijack_nondata(const struct mac_driver *r)
{
	if (usbstick_mode.raw)
		mac_802154raw(r);
}


/*--------------------------------------------------------------------*/
/*--------------------------------------------------------------------*/
/** \brief Logs a sent 6lowpan frame
 *
 *  This routine passes a frame 
 *  directly to the ethernet layer without decompressing.
 */
void mac_logTXtoEthernet(frame_create_params_t *p,frame_result_t *frame_result)
{
  uint8_t sendlen;

  /* Make sure we are supposed to do this */
  if (usbstick_mode.raw == 0) return;

/* Get the raw frame */
  memcpy(&raw_buf[UIP_LLH_LEN], frame_result->frame, frame_result->length);
  sendlen = frame_result->length;

 //Setup generic ethernet stuff
  ETHBUF(raw_buf)->type = htons(UIP_ETHTYPE_802154);
  
  uint64_t tempaddr;
	
 
  //Check for broadcast message
  //if(rimeaddr_cmp((const rimeaddr_t *)destAddr, &rimeaddr_null)) {
  if(  ( p->fcf.destAddrMode == SHORTADDRMODE) &&
       ( p->dest_addr.addr16 == 0xffff) ) {
    ETHBUF(raw_buf)->dest.addr[0] = 0x33;
    ETHBUF(raw_buf)->dest.addr[1] = 0x33;
    ETHBUF(raw_buf)->dest.addr[2] = UIP_IP_BUF->destipaddr.u8[12];
    ETHBUF(raw_buf)->dest.addr[3] = UIP_IP_BUF->destipaddr.u8[13];
    ETHBUF(raw_buf)->dest.addr[4] = UIP_IP_BUF->destipaddr.u8[14];
    ETHBUF(raw_buf)->dest.addr[5] = UIP_IP_BUF->destipaddr.u8[15];
  } else {    

	tempaddr = p->dest_addr.addr64;
	
	byte_reverse((uint8_t *)&tempaddr, 8);
	
	//Otherwise we have a real address
	mac_createEthernetAddr((uint8_t *) &(ETHBUF(raw_buf)->dest.addr[0]),
            (uip_lladdr_t *)&tempaddr);

  }

	tempaddr = p->src_addr.addr64;
	
	byte_reverse((uint8_t *)&tempaddr, 8);

  mac_createEthernetAddr((uint8_t *) &(ETHBUF(raw_buf)->src.addr[0]),
                         (uip_lladdr_t *)&tempaddr);

   PRINTF("Low2Eth: Sending 802.15.4 packet to ethernet\n");

  sendlen += UIP_LLH_LEN;

  rndis_send(raw_buf, sendlen);
  rndis_stat.rxok++;
 
  return;
}


/*--------------------------------------------------------------------*/
/** \brief Process a received 6lowpan packet. 
 *  \param r The MAC layer
 *
 *  The 6lowpan packet is put in rimebuf by the MAC. This routine passes
 *  it directly to the ethernet layer without decompressing.
 */
void mac_802154raw(const struct mac_driver *r)
{ 
  uint8_t sendlen;

	parsed_frame = sicslowmac_get_frame();

  /* Get the raw frame */
  memcpy(&raw_buf[UIP_LLH_LEN], radio_frame_data(), radio_frame_length());
  sendlen = radio_frame_length();

 //Setup generic ethernet stuff
  ETHBUF(raw_buf)->type = htons(UIP_ETHTYPE_802154);
  
 
  //Check for broadcast message
  //if(rimeaddr_cmp((const rimeaddr_t *)destAddr, &rimeaddr_null)) {
  if(  ( parsed_frame->fcf->destAddrMode == SHORTADDRMODE) &&
       ( parsed_frame->dest_addr->addr16 == 0xffff) ) {
    ETHBUF(raw_buf)->dest.addr[0] = 0x33;
    ETHBUF(raw_buf)->dest.addr[1] = 0x33;
    ETHBUF(raw_buf)->dest.addr[2] = UIP_IP_BUF->destipaddr.u8[12];
    ETHBUF(raw_buf)->dest.addr[3] = UIP_IP_BUF->destipaddr.u8[13];
    ETHBUF(raw_buf)->dest.addr[4] = UIP_IP_BUF->destipaddr.u8[14];
    ETHBUF(raw_buf)->dest.addr[5] = UIP_IP_BUF->destipaddr.u8[15];
  } else {
    
	//Otherwise we have a real address
	mac_createEthernetAddr((uint8_t *) &(ETHBUF(raw_buf)->dest.addr[0]),
            (uip_lladdr_t *)rimebuf_addr(RIMEBUF_ADDR_RECEIVER));

  }

  mac_createEthernetAddr((uint8_t *) &(ETHBUF(raw_buf)->src.addr[0]),
                         (uip_lladdr_t *)rimebuf_addr(RIMEBUF_ADDR_SENDER));

   PRINTF("Low2Eth: Sending 802.15.4 packet to ethernet\n");

  sendlen += UIP_LLH_LEN;

  rndis_send(raw_buf, sendlen);
  rndis_stat.rxok++;
 
  return;
}


uint8_t memcmp_reverse(uint8_t * a, uint8_t * b, uint8_t num)
{
	uint8_t i = 0;

	while(num) {
		num--;
		if (a[i] != b[num]) return 1;
		i++;
	}
	
	return 0;
}

/** @} */



/** @} */