ARPHeader.cc

/***************************************************************************
 * ARPHeader.cc -- The ARPHeader Class represents an ARP packet. It        *
 * contains methods to set any header field. In general, these methods do  *
 * error checkings and byte order conversion.                              *
 *                                                                         *
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 ***************************************************************************/
/* This code was originally part of the Nping tool.                        */

#include "ARPHeader.h"

/******************************************************************************/
/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS                        */
/******************************************************************************/
ARPHeader::ARPHeader() {
  this->reset();
} /* End of ARPHeader constructor */


ARPHeader::~ARPHeader() {

} /* End of ARPHeader destructor */


/** Sets every attribute to its default value */
void ARPHeader::reset(){
  memset (&this->h, 0, sizeof(nping_arp_hdr_t));
  this->length=ARP_HEADER_LEN;
} /* End of reset() */


/******************************************************************************/
/* PacketElement:: OVERWRITTEN METHODS                                        */
/******************************************************************************/

/** @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 *ARPHeader::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 ARPHeader class is able to hold a maximum of 28 bytes.
  * If the supplied buffer is longer than that, only the first 28 bytes will be
  * stored in the internal buffer.
  * @warning Supplied len MUST be at least 28 bytes (ARP header length).
  * @return OP_SUCCESS on success and OP_FAILURE in case of error */
int ARPHeader::storeRecvData(const u8 *buf, size_t len){
  if(buf==NULL || len<ARP_HEADER_LEN){
    return OP_FAILURE;
  }else{
    this->reset(); /* Re-init the object, just in case the caller had used it already */
    this->length=ARP_HEADER_LEN;
    memcpy(&(this->h), buf, ARP_HEADER_LEN);
  }
 return OP_SUCCESS;
} /* End of storeRecvData() */


/* Returns a protocol identifier. This is used by packet parsing funtions
 * that return linked lists of PacketElement objects, to determine the protocol
 * the object represents. */
int ARPHeader::protocol_id() const {
    return HEADER_TYPE_ARP;
} /* End of protocol_id() */


/** Determines if the data stored in the object after an storeRecvData() call
  * is valid and safe to use. This mainly checks the length of the data but may
  * also test the value of certain protocol fields to ensure their correctness.
  * @return the length, in bytes, of the header, if its found to be valid or
  * OP_FAILURE (-1) otherwise. */
int ARPHeader::validate(){
  if( this->length!=ARP_HEADER_LEN)
    return OP_FAILURE;
  else
    return ARP_HEADER_LEN;
} /* End of validate() */


/** Prints the contents of the header and calls print() on the next protocol
  * header in the chain (if there is any).
  * @return OP_SUCCESS on success and OP_FAILURE in case of error. */
int ARPHeader::print(FILE *output, int detail) const {
  fprintf(output, "ARP[]");
  if(this->next!=NULL){
    print_separator(output, detail);
    next->print(output, detail);
  }
  return OP_SUCCESS;
} /* End of print() */


/******************************************************************************/
/* PROTOCOL-SPECIFIC METHODS                                                  */
/******************************************************************************/

/** Sets HardwareType.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHardwareType(u16 val){
  this->h.ar_hrd=htons(val);
  return OP_SUCCESS;
} /* End of setHardwareType() */


/** Sets HardwareType to ETHERNET.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHardwareType(){
  this->h.ar_hrd=htons(HDR_ETH10MB);
  return OP_SUCCESS;
} /* End of setHardwareType() */


/** Returns value of attribute h.ar_hrd */
u16 ARPHeader::getHardwareType(){
  return ntohs(this->h.ar_hrd);
} /* End of getHardwareType() */


/** Sets ProtocolType.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtocolType(u16 val){
  this->h.ar_pro=htons(val);
  return OP_SUCCESS;
} /* End of setProtocolType() */


/** Sets ProtocolType.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtocolType(){
  this->h.ar_pro=htons(0x0800); /* DEFAULT: IPv4 */
  return OP_SUCCESS;
} /* End of setProtocolType() */


/** Returns value of attribute h.ar_pro */
u16 ARPHeader::getProtocolType(){
  return ntohs(this->h.ar_pro);
} /* End of getProtocolType() */


/** Sets HwAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHwAddrLen(u8 val){
  this->h.ar_hln=val;
  return OP_SUCCESS;
} /* End of setHwAddrLen() */


/** Sets HwAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHwAddrLen(){
  this->h.ar_hln=ETH_ADDRESS_LEN;
  return OP_SUCCESS;
} /* End of setHwAddrLen() */


/** Returns value of attribute h.ar_hln */
u8 ARPHeader::getHwAddrLen(){
  return this->h.ar_hln;
} /* End of getHwAddrLen() */


/** Sets ProtoAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtoAddrLen(u8 val){
  this->h.ar_pln=val;
  return OP_SUCCESS;
} /* End of setProtoAddrLen() */


/** Sets ProtoAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtoAddrLen(){
  this->h.ar_pln=IPv4_ADDRESS_LEN; /* DEFAULT: IPv4 */
  return OP_SUCCESS;
} /* End of setProtoAddrLen() */


/** Returns value of attribute h.ar_pln */
u8 ARPHeader::getProtoAddrLen(){
  return this->h.ar_pln;
} /* End of getProtoAddrLen() */


/** Sets OpCode.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setOpCode(u16 val){
  this->h.ar_op=htons(val);
  return OP_SUCCESS;
} /* End of setOpCode() */


/** Returns value of attribute h.ar_op */
u16 ARPHeader::getOpCode(){
  return ntohs(this->h.ar_op);
} /* End of getOpCode() */


/** Sets SenderMAC.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setSenderMAC(const u8 * val){
  if(val==NULL)
    return OP_FAILURE;
  memcpy(this->h.data, val, ETH_ADDRESS_LEN);
  return OP_SUCCESS;
} /* End of setSenderMAC() */


/** Returns value of attribute h.ar_sha */
u8 * ARPHeader::getSenderMAC(){
  return this->h.data;
} /* End of getSenderMAC() */


/** Sets SenderIP.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setSenderIP(struct in_addr val){
  memcpy(this->h.data+6, &val.s_addr, 4);
  return OP_SUCCESS;
} /* End of setSenderIP() */


/** Returns value of attribute h.ar_sip */
u32 ARPHeader::getSenderIP(){
  u32 *p = (u32 *)(this->h.data+6);
  return *p;
} /* End of getSenderIP() */


/** Sets TargetMAC.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setTargetMAC(u8 * val){
  if(val==NULL)
    return OP_FAILURE;
  memcpy(this->h.data+10, val, ETH_ADDRESS_LEN);
  return OP_SUCCESS;
} /* End of setTargetMAC() */


/** Returns value of attribute h.ar_tha */
u8 * ARPHeader::getTargetMAC(){
  return this->h.data+10;
} /* End of getTargetMAC() */


/** Sets TargetIP.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setTargetIP(struct in_addr val){
  memcpy(this->h.data+16, &val.s_addr, 4);
  return OP_SUCCESS;
} /* End of setTargetIP() */


/** Returns value of attribute h.ar_tip */
u32 ARPHeader::getTargetIP(){
  u32 *p = (u32 *)(this->h.data+16);
  return *p;
} /* End of getTargetIP() */