
/***************************************************************************
 * EthernetHeader.cc -- The EthernetHeader Class represents an Ethernet    *
 * header and footer. It contains methods to set the different header      *
 * fields. These methods tipically perform the necessary error checks and  *
 * byte order conversions.                                                 *
 *                                                                         *
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 ***************************************************************************/

#include "EthernetHeader.h"
#include "nping.h"
#include "common.h"
#include "utils_net.h"


EthernetHeader::EthernetHeader(){
  this->reset();
} /* End of EthernetHeader constructor */


EthernetHeader::~EthernetHeader(){

} /* End of EthernetHeader destructor */


/** Sets every class attribute to zero */
void EthernetHeader::reset(){
  memset(&this->h, 0, sizeof(nping_eth_hdr_t));
  memset(&this->f, 0, ETH_FOOTER_LEN );
  this->length=14; /* We don't count the crc yet */
} /* End of reset() */


/** @warning This method is essential for the superclass getBinaryBuffer()
 *  method to work. Do NOT change a thing unless you know what you're doing  */
u8 * EthernetHeader::getBufferPointer(){
  return (u8*)(&h);
} /* End of getBufferPointer() */


/** Stores supplied packet in the internal buffer so the information
  * can be accessed using the standard get & set methods.
  * @warning  The EthernetHeader class is able to hold a maximum of 14 bytes.
  * If the supplied buffer is longer than that, only the first 14 bytes will be
  * stored in the internal buffer.
  * @warning Supplied len MUST be at least 14 bytes (Ethernet header length).
  * @return OP_SUCCESS on success and OP_FAILURE in case of error */
int EthernetHeader::storeRecvData(const u8 *buf, size_t len){
  if(buf==NULL || len<ETH_HEADER_LEN){
    return OP_FAILURE;
  }else{
    this->reset(); /* Re-init the object, just in case the caller had used it already */
    this->length=ETH_HEADER_LEN;
    memcpy(&(this->h), buf, ETH_HEADER_LEN);
  }
 return OP_SUCCESS;
} /* End of storeRecvData() */


/** Sets Source MAC address
 *  @warning Supplied buffer must contain at least 6 bytes */
int EthernetHeader::setSrcMAC(const u8 *m){
  if(m==NULL)
    outFatal(QT_3, "EthernetHeader::setSrcMAC(u8*): NULL value supplied ");
  memcpy(h.eth_smac, m, 6);
  return OP_SUCCESS;
} /* End of setSrcMAC() */


/** Sets Source MAC address. If it receives "rand", a random MAC is set.
 *  @warning Supplied buffer must have format "FF:FF:FF:FF:FF:FF" */
int EthernetHeader::setSrcMAC_str(char *p){
  u8 dummy[6];
  if(p==NULL)
    outFatal(QT_3, "EthernetHeader::setSrcMAC(char *): NULL value supplied ");
  if( parseMAC(p, dummy) != OP_SUCCESS )
    return OP_FAILURE;
  memcpy(h.eth_smac, dummy, 6);
  return OP_SUCCESS;
} /* End of setSrcMAC() */


/** Returns source port in HOST byte order
 *  @warning Returned pointer points directly to a Class internal buffer. If
 *  contents are changed, the instance of the class will be affected. */
u8* EthernetHeader::getSrcMAC(){
  return this->h.eth_smac;
} /* End of getSrcMAC() */


/** Sets Destination MAC address
 *  @warning Supplied buffer must contain at least 6 bytes */
int EthernetHeader::setDstMAC(u8 *m){
  if(m==NULL)
    outFatal(QT_3, "EthernetHeader::setDstMAC(u8 *): NULL value supplied ");
  memcpy(h.eth_dmac, m, 6);
  return OP_SUCCESS;
} /* End of setDstMAC() */


/** Sets destination port. If it receives "rand", a random destination port is set.
 *  @warning MAC must be supplied in host byte order. This method performs
 *  byte order conversion using htons() */
int EthernetHeader::setDstMAC(char *p){
  u8 dummy[6];
  if(p==NULL)
    outFatal(QT_3, "EthernetHeader::setDstMAC(char *): NULL value supplied ");
  if( parseMAC(p, dummy) != OP_SUCCESS )
    return OP_FAILURE;
  memcpy(h.eth_dmac, dummy, 6);
  return OP_SUCCESS;
} /* End of setDstMAC() */


/** Returns destination port in HOST byte order */
u8 *EthernetHeader::getDstMAC(){
  return this->h.eth_dmac;
} /* End of getDstMAC() */


int EthernetHeader::setEtherType(u16 val){
  h.eth_type=htons(val);
  return OP_SUCCESS;
} /* End of setEtherType() */


/** Returns destination port in HOST byte order */
u16 EthernetHeader::getEtherType(){
  return this->h.eth_type;
} /* End of getEtherType() */


/** @warning Sum is set to supplied value with NO byte ordering conversion
 *  performed. */
int EthernetHeader::setSum(u32 s){
  this->f.crc=s;
  return OP_SUCCESS;
} /* End of setSum() */


/* TODO: Finish implementation */
int EthernetHeader::setSum(){
  f.crc = 0;
  //int bufflen;
  //u8 aux[ MAX_IP_PACKET_LEN + 14 + 4  ];

  /* Copy packet contents to a buffer */
  //bufflen=this->dumpToBinaryBuffer(aux, MAX_IP_PACKET_LEN + 14 + 4);

  /* Compute checksum */
  // f.crc = crc32...
  return OP_SUCCESS;
} /* End of setSum() */


int EthernetHeader::setSumRandom(){
  while( (this->f.crc=get_random_u32())==0 ); /* Discard value zero */
  return OP_SUCCESS;
} /* End of setSumRandom() */


u32 EthernetHeader::getSum(){
  return this->f.crc;
} /* End of getSum() */

